Update: Principles governing the cost control of dispute resolution and claim settlement involving experts

I updated the Principles after being contacted by a Toronto firm about a slip and fall accident. The question came up about being retained on contingency. The contact said they do this when the injured party may have a claim but no money to pursue their rights. He also thought the claim would settle within a year. I told him I couldn’t do this.

The chap was pleasant but I thought later, after he remarked he was acting for a partner in the firm, that he may have been a more junior member of the firm and just didn’t know: Experts don’t take cases on contingency, and slip and fall cases typically take more than a year to settle.

Common law requires that experts: (Ref. 1)

  1. Be independent from the parties that retain them
  2. Provide objective, unbiased opinion evidence in relation only to matters within their expertise, and,
  3. Avoid assuming the role of advocate for the parties that retain them

These requirements are the same in all issues involving dispute resolution and claim settlement. The great majority of experts know that they serve the process, as found in a pilot study of 152 Canadian experts, not the party who retained them. (Ref. 2)

The requirements also mean that an expert must engage on a fee basis not on a contingency basis.

But, to be absolutely sure that there wasn’t another school of thought out there on experts and contingency I contacted the head of another Toronto law firm. I haven’t been answered – slammed would be more correct – as quickly as in this case: “Absolutely not!”.

After all this, I thought, I better update the Principles to be sure it’s clear when managing cost that experts are not retained on a contingency basis.

You can read the updated Principles at http://www.ericjorden.com/blog/2019/07/30/principles-governing-the-cost-control-of-dispute-resolution-and-claim-settlement-involving-experts/ as originally posted on July 30, 2019.


  1. Stockwood, Q.C., David, Civil Litigation, A Practical Handbook, 5th ed, 2004, Thompson Carswell
  2. Corbin, Ruth M., Chair, Corbin Partners Inc. and Adjunct Professor, Osgoode Hall School, Toronto, Breaking the Expert Evidence Logjam: Experts Weigh In, presented at Expert Witness Forum East, Toronto, February, 2018


  1. Jorden, Eric E., Consulting professional engineer; forensic engineer, Geotechnology Ltd., Halifax, Principles Governing the Cost Control of Dispute Resolution and Claim Settlement Involving Experts, presented at the Expert Witness Forum East, Toronto, February, 2018

(Updated September 23, 2020 by Eric E. Jorden, M.Sc., P.Eng, Halifax, N.S. Canada.  E: ejorden@eastlink.ca)

Get on site and do a forensic visual assessment before COVID-19 returns

There’s an argument for getting on site and doing a visual assessment before COVID-19 returns. There is talk of a second wave. I thought this when I was thinking of getting up to New Brunswick to visit friends before I get COVID-19-stayed in Halifax for the winter.

There’s no question about the value of virtual site assessments as I noted recently. (Refs 1, 2) Studying emailed documents and photographs of a site and getting a lot of data without leaving the office. Including the cause of a slip and fall accident that stared me in the face recently. (Ref. 1)

But, the worth of an on-scene visual assessment has been well understood for decades – if it can be done safely. Pre, second-wave COVID-19 would be safe. (Ref. 3)

Getting on site would give us:

  • additional photographs to those in the documents,
  • aerial video – pre-planned with a virtual drone flight (Ref. 4),
  • accurate measurements,
  • re-enactment of a slip and fall accident, if that’s the issue,
  • a forensic engineer calibrated to the site (Ref. 5), and,
  • more hard data for continued virtual site assessment back in the office.

In many cases, a forensic investigation unfolding in this conventional way – document study then an on-site visual assessment – often points to the cause of a problem and those responsible. And often, as well, to how an insurance claim might unfold or whether a civil case should be filed. Additional intrusive investigation at the scene is sometimes needed but not always.

So, what are we waiting for? If a second COVID-19 wave is in the wings ready to wash over us, and we quickly visit friends in the Atlantic bubble to get ahead of it, why aren’t we quickly doing an on-site visual assessment?


  1. What can you get from a virtual visual examination of an accident scene? Posted August 28, 2020 2. It’s here
  2. COVID-19 and forensic engineering investigation. Posted May 7, 2020
  3. COVID-19 and an initial forensic task a.k.a a visual site assessment, sans social distancing. Posted June 1, 2020
  4. It’s here, cost effective, efficient aerial video for forensic investigation! Posted October 8, 2019
  5. Can you “calibrate” a forensic expert? Posted June 23, 2020

What can you get from a virtual visual examination of an accident scene?

In these COVID-19 times, why not “stay home”, as we’re told, and do a virtual visual examination of a failure or accident scene? Simply read the documents and study the photographs then hypothesize cause, at least initially.

Recognize the document study for what it is, a virtual visual examination, and accept it as a quite valid task in a forensic investigation. At least in the short term, in the interest of staying safe.

There’s no question a lonely expert can still go to a scene and do a visual examination, get a wealth of data and be quite safe. (Ref. 1) It’s just that a virtual visual examination of a site is good in the beginning too, can sometimes, unexpectedly, see the cause, and is less expensive.


I thought this recently when I was contacted and read the emailed documents on a slip and fall accident and studied attached photographs. I realized this was a virtual visual examination of the scene. The probable cause of the accident was obvious in this case. The party responsible was possibly lurking in the wings, virtually visible too.

It was also easy to identify the three field tasks that would need to be done during a complete forensic investigation of the slip and fall and the data that would be got from each. Also a fourth office task.

  1. Visit and visually examine and measure the accident scene for real, and take more photographs – and also get calibrated to the scene as I blogged recently (Ref. 2)
  2. Examine construction of other similar facilities in the area
  3. Re-enact the accident at the scene
  4. Assess the standard of care in the office for design and construction of similar facilities

So, the cause, the parties involved and the tasks necessary for a full scale forensic investigation. All this from a document review – a virtual visual examination of the accident scene without leaving the office.

It’s a way of thinking in keeping with these COVID-19 times.


  1. COVID-19 and an initial forensic task a.k.a a visual site assessment, sans social distancing. Posted June 6, 2020
  2. Can you “calibrate” a forensic expert? Posted June 23, 2020

Why the surprise about the mud slide in BC?

I was surprised that a house was built in the path of the mud slide in British Columbia early this month, July 4th.  Built right in a mud channel.  Particularly in view of the fact that the Ministry of Transport reported that more slides were possible – they knew. (Ref. 1) Why were houses approved for construction in such an unstable area?  Who is liable?

Assessing the potential for a mud slide in an area and quantifying the risk for residents is not rocket science.  Someone had done sufficient assessment to warrant the report of the Ministry.

You don’t see the messy stuff mentioned as such in engineering books but it’s there.  It’s classified as very soft clay and silt with a little sand and gravel and a few cobbles.  The analytical procedures are in the books too – reliable slope stability methods of analysis understood by experienced engineers.

So, what’s the big surprise about the mess in BC and why were people allowed to build there?  We’re not talking something small here.  We’re talking about a slide that engulfed a house to a depth of several feet according to pictures on line.  And moving fast too as seen in one video of a fellow running out of the way just in time.

You don’t need a lot of data to do such an analysis either and the data is readily available in the public domain:

  • The history of mud slides in the area and the rain fall at the time
  • Topographic maps to give you the shape and slope of the ground, and the location of mud channels
  • The results of terrain analysis identifying features relevant to mud slides, and evidence of past events (screen grabs from video taken from low flying drones has had a big impact on the engineering analysis of terrain in an area)
  • Soil maps (surficial geology maps) to tell you that a mixture of clay and silt underlies the area

Engineers have done this type of assessment often, and everywhere throughout North American and around the world.  And based on the news and Transportation’s report, likely for this area as well.

So why the surprise?

Why would a person even mistakenly build a house in a mud channel?  I can’t help but think there would be local knowledge that would kick in even if the government was silent.  Would you build a house in a river channel or on a flood plain between wet seasons?


  1. Notes taken from a CBC News report online.  “Debris flood, a mix of mud, gravel and cobbles 200 km east of Prince George, BC in a flood prone area 1:30 Saturday morning July 4, 2020.  Waist deep.  Second one that day nearby.  Ministry of Transport said more likely in the area”

You could be excused for thinking that everything is falling down

We recently learned about the potential for failures and accidents in the built environment.  There are 1,000s of different ways these can happen based on the great number of structures that are out there – at least 124. (Ref. 1)  But where are the failures?  Where’s the evidence this might be happening?

It would seem to be all around you as you drive and walk in your neighbourhood, your community, your town and your city.  And you can’t escape the evidence by taking a break in the country.  It’s there too.

By way of bringing you up to speed, I describe a few failures and accidents below, in some cases with a typical cause noted.  I’ve classified them according to whether they were:

  • Small
  • Medium
  • Large and Catastrophic
  • Personal or,
  • Stupid
  • The Reality

A. Small Failures

1. Manholes and catch basins in the street are sometimes higher or lower than the road surface by a few inches.  They are design or construction failures.

Car drivers in trying to avoid the bump sometimes have accidents.

2. A narrow depression a few inches deep across a road – sort of like a hollow, upside down speed bump – is a failure.  You know them from the bump-bump as you drive across.  They are located above trenches where storm and sanitary sewers and water pipes have been installed.

The depressions result from poor compaction of the soil placed in the trench to fill it after the sewers and water pipes are installed – a construction failure.

They can also cause motor vehicle accidents.

3. Pot holes in roads are a design or construction failure.

They’re due to a weak pavement and subgrade or a poorly drained subgrade.

It’s interesting, pot holes can “grow” larger after water collects in them.  The water helps soil stick to the wheel of a vehicle as it drives in and out of the pot hole.

4. Broken pavement in public parking lots and private driveways are failures.

In the case of parking lots, the failure is due either to inadequate design or construction.  In the case of driveways, it’s due to inadequate construction.

Like pot holes, the pavement and subgrade are weak or the subgrade is poorly drained or both.

5. Sloping floors in houses or apartments are failures.

They’re due to inadequate construction – an 11″ slope from one end to the other in one house that I examined.  The mistake was found in time but not corrected.

6. Wet basements and leaking roofs are failures, of course.

B. Medium Failures

1. The floors of a multistory building, a high-rise, slope and sag at least an estimated 2 and 3 inches – a failure.

I know how high-rises are constructed, and in this case I also learned about the tight schedule the contractor was under to get it up.  This was probably a construction failure that unfolded as the floors went up.

There’s an increased risk of slip and fall accidents on sloping floors, particularly if they’re wet.

2. The concrete block and brick walls of buildings sometimes crack – a failure in some cases

The large size and configuration of some cracks point to inadequate design or construction.  Tiny cracks are usually normal.

3. The foundations of all manner of structures sometimes fail.  The failures are marked by excessive foundation settlement or total, catastrophic collapse.

A little settlement is normal.  Excessive settlement damages the structure above.  Collapse destroys the structure.

These types of failures are often due to inadequate geo-investigation of the foundation soils but sometimes due to inadequate foundation design or construction.

4. Uneven sidewalks are due to inadequate design or construction of the subgrade support or to poor drainage.

The unevenness is quite noticeable when the sidewalk is constructed of concrete slabs and one slab is a little higher or lower than the next at a joint – and easy to trip over.

I’ve classified these as medium failures because of the increased risk of trip and fall accidents.

5. The three Edmonton bridge girders that bent sideways during construction on March 15, 2015 was a failure.  No one was injured because the construction workers went home due to a wind storm.  A crane was left standing with it’s cable and strap connected to the outside girder of the three.

Although I was not involved in the investigation of this failure, I did study photographs on line and in newspapers and conferred with structural engineers and bridge designers.  I also examined the bridge from a security fence while visiting my daughter in Edmonton.

I concluded – an initial hypothesis – the wind caused the crane’s boom to vibrate and the strap to repeatedly tug on the girder and in time bend it sideways.  The outer girder was connected to the other girders causing them to bend too.  This was a construction failure.

6. The St. John river in New Brunswick sometimes floods in the spring and causes damage downstream.  Some people wondered during the flood of 2019 if it could be due to operation of the Mactaquac dam and reservoir upstream of Fredericton.

The dam was constructed to generate electricity when water pressure on the dam’s turbines cause them to turn.  The greater the pressure the faster they turn the more electricity generated.  The greater the depth of water in the reservoir behind the dam the greater the water pressure.

There would be interest in the operation of the dam in maintaining as great a depth of water as possible.  But, too great a depth would threaten over-topping of the dam and collapse – a failure.  Not good.

Water is released from the reservoir to prevent this.  But some years melting snow and rain in the watershed would cause the depth of water in the reservoir to rise more quickly.  The need to release water would get quite pressing.  The reluctance to do this would still be there because water depth/pressure is hydro power.

I can’t help but think these conflicting interests would have something to do with flooding of the St. John river.

7. Rain water flooded the electrical service rooms of a medical practice.  My investigation included uncovering the PVC pipe carrying the power lines into the rooms.  This revealed water seeping in around the outside of the pipe where it passed through the exterior wall.  Further investigation found evidence of rain water inside the pipe.

Water wasn’t supposed to be there because the top of the pipe on the outside wall where the power lines entered from the street was covered by a canopy.  Falling rain was shed by the canopy.

This was fine except a driving rain storm out of the southeast has rain soaked up-gusts.  These gusts of wind carry water up under the canopy and into the top of the PVC pipe and down the pipe and into the electrical rooms – a canopy design failure.

It’s interesting that the inadequate design was recognized during construction.  Steps were taken to accommodate the defect and it was a good solution.  Except, another problem developed involving the electric lines that breached the good solution after it was implemented.

At the end of the day, definitely a canopy design failure aided and abetted by construction failure of what seemed like a good idea.  Explaining all these issues would make your eyes glaze over so I’ll stop here.

8. The slump of soil on a cut slope along a highwaya mini landslide – is a design failure.

You sometimes see these along our highways.  They are often due to excavating the slope too steeply for the natural angle of repose of the soil, or poor drainage of the slope.  These types of failures can be up there with a catastrophic failure.

C. Large and Catastrophic Failures

1. The debris flood that happened in British Columbia early Saturday morning July 4th was a failure.  A waist high mix of mud, gravel and cobbles slid off the mountain and covered a residential property.  Another slide also occurred in the area.  The Ministry of Transport reported the likelihood of additional slides.

The slide could be attributed to poor planning years ago in allowing houses to be built in a slide-prone area in the first place or poor maintenance in not monitoring conditions like rainfall that precipitate landslides.

2. The bridge linking Canso to Durell’s Island in Nova Scotia that collapsed Tuesday July 7th was a failure.  The bridge fell down as a truck drove over it hauling a flatbed trailer loaded with a crane.

The failure was likely due to either the live load of the truck, flatbed and crane exceeding the design live load of the bridge or maintenance of the bridge or a combination.

(A live load is the weight to which a structure is subjected periodically in addition to its own dead load/weight which is always there)

3. I investigated the cause of a bridge collapse in a residential area.  A woman was injured when she drove onto the bridge debris in the stream below.

The failure was due to corrosion of the steel in the bridge that was missed during inspection and maintenance.

4. The crane that collapsed onto a multistory building in Halifax in 2019 was a failure.  It came to rest draped over the front of the building, over the top and down the other side.  The crane broke/bent at several locations along it’s length during the failure.

I am not involved in the investigation of this failure but from a distance outside the security fence it was easy to imagine – an initial hypothesis – that the wind that night, a live load, was too great for the crane.  It looked like an older crane and steel corrosion might be suspect too.

5. High retaining walls that collapse and fall down are usually design failures.  The base of one that collapsed on the coast of Nova Scotia a few years ago was too narrow.

Low retaining walls typical of residential landscaping that lean too much are construction failures and often due to inadequate drainage.

6. A man climbed a step ladder to do some work above a hung ceiling in a building.  He fell, hit his head on the concrete floor and died instantly.  One of the ladder’s legs was bent.

I was retained to investigate the cause of the accident.  There were no witnesses to report on whether or not the workman leaned one way or the other while on the ladder nor how far he had climbed up the ladder.

The bent leg and a leaning workman near the top of the ladder were of course initially suspect.  I planned a re-enactment of the accident with a professional stuntman however my client resolved a dispute arising from the accident in another way.

7. Ice falling off a roof and hitting and severely injuring a person is a maintenance failure.

8. A landslide that takes a house down with it is a catastrophic failure.

I investigated the cause of one like this on the coast of New Brunswick.  It was due to erosion of the toe of the natural slope by the Bay of Fundy.

The landslide was not an act of God because it could have been foreseen and prevented, or avoided by building elsewhere.

D. Personal Accidents

1. I was cleaning snow off the back of my neighbour’s car in his sloping driveway two winters ago.  He gets up a bit late.  I was out doing some shoveling so I thought I might as well.

I started to slide sideways down the slope towards the street.  As it turns out on some black ice.  I did good until I got to the windrow of snow left by the snow plow, fetched up and fell hard.

I like to think to this day that if I had been on skis I would not have fallen considering that East Coast ski hills have some icy runs.

My accident alerted me to the accidents waiting to happen on sloping, paved driveways – surfaces, in general, used by people –  due to black ice, due to questionable design and construction.

I see in recent years steel plates with roughed surfaces being installed on sloping sidewalks at intersections.  Smart.

E. Stupid Accidents

1. Three months after investigating the step ladder fatality I was up a step ladder putting the finishing touches on construction of a storage shed on my property.  I was nailing the fascia board in place and leaned sideways on the ladder to drive that last nail at the end when down I went.

I was lucky and didn’t hit any of the cobbles exposed at the ground surface but I did hit the ground hard and lay there for a while.  My ladder was not defective – no component failure, no bent legs – just my use of the ladder.


The Reality

There’s a lot of things broken and not working as they should.  It’s important to know this and that it’s all around us, even out in the country.  Also, that it’s our fault, we designers, builders and operators.  But know too, that the very great bulk of the built environment works just fine, thank you very much, and that’s due to us too, we folk who live in the built environment.  There is the potential for 1,000s of failures but they don’t happen because we get it right almost all the time.


  1. What’s in “…the built environment” and how many ways can it fail?  Posted July 8, 2020







What’s in “…the built environment” and how many ways can it fail?

On occasion, when blogging about the nature and methods of forensic investigation, I’ve wondered, just how many different structures are there in the built environment?  And are some more difficult to design and build than others?  If so, are some more prone to accidents and failures than others?

I have answers of sorts in the following.  But, like me, you are unlikely to believe anything more than an estimate even if I were to try that.


A structure is something (such as a building) that is built by people. It’s also a place where accidents and failures can happen.

Tunnels, bridges, canals, retaining walls and towers are all structures.  Also cars, trucks, helicopters and trains.  And patios, decks and raised flower beds.

It might also be something in the natural environment that is used by people.  Like the foundation soils supporting a building or a tower.  Also the slopes off to the left or right along our highways.

It’s usually a cut slope if it rises from the highway – the natural soil has been cut into or excavated to form the slope.  It’s a fill slope if it drops away from the highway – excavated soil has been dumped there and forms a slope.  These slopes assume the angle of repose of the soil, which varies for different soils.

All this excavating and dumping to construct a highway – another structure – so it can get to where it’s going.


One source listed 124 different engineering projects and classified these according to their complexity from Least Complex (#1) to Most Complex (#4). (Ref. 1) The classification took into account the number of parts or stages making up a project, their interrelationship, and the effort involved in analysing, designing and constructing the project.  Generally, the more parts, the more complex.

Examples of Level #1 are simple commercial buildings and storm and sanitary sewers, and of Level #3, ferry terminals, grain silos and small dams.

Almost all engineering projects involve a structure as distinct from a system or process, like a computer network.

Some of the interrelated parts of a bridge include the foundations soils, the foundations, the abutments, the piers and the bridge deck.

If it’s a suspension bridge like across Halifax Harbour there are also the main cables, the towers above the piers supporting the main cables, the anchors on the bank or shore at the ends of the cables and the vertical, suspender cables that tie the bridge deck to the main cables. (Ref. 2)


The next time I was driving after drafting the above I noted still more structures not included in the count of 124.  Albeit smaller ones like traffic lights at an intersection, gates at railway crossings, tall propane storage tanks at service stations and armored stone on an eroding shore line.  But still structures that can fail in some way or result in an accident.

And failures or accidents can happen at any of the 10 stages in the life of a structure, not just during the construction stage or service stage. (Ref. 3)


If a building, a single structure, can fail in 209 ways, excluding what happens in the basement (Ref. 4, 5), how many ways can each of the 124 different structures in the built environment fail, during each of the 10 stages in the life of each structure?  What would the total look like?

Just think of those 124 structures each with several interrelated parts and each part with several components.  A component that doesn’t work properly or breaks completely is a failure.

The stairs in a building are a component of the building structure.  The chute at the bottom of a grain silo is a component of the silo.  The railing along the edge of a bridge deck that prevents you driving or falling into the river or harbour is a component of the bridge structure.

The National Research Council of Canada found in a study that the lowly, humble basement of a building can fail in hundreds of ways. (Ref. 6)  What does that tell you about the number of ways failure can happen in the built environment?

(It occurred to me on reading this 185 page report that the study procedures and processes are a guide for analysing the cause of failures and accidents in structures, in general, other than just basements)


I was tempted but refrained from trying to multiply some of these numbers together to get an estimate of the likely 1,000s of ways failure can occur in the built environment.  It boggles the mind.

Thank heaven we also have good engineering in the built environment and most of the 124+ structures and the many ways each can fail – at least 209 for a building – get through the 10 stages of their life without failure or accident.  We don’t want failures but they do occur and engineers learn from them.


  1. Guideline For Engagement of Consulting Engineering Services, CENS, Consulting Engineers of Nova Scotia, Halifax, NS
  2. Personal communication, Jamie Yates, Yates Consulting Engineering, Fall River, Nova Scotia, June, 2020
  3. Stages in the “life” of a structure helps communication between counsel, insurance claims manager and an engineering expert. Posted July 2, 2015
  4. How many ways can a building fail, and possibly result in civil litigation or an insurance claim? Posted July 10, 2014
  5. Nicastro, David H., ed., Failure Mechanisms in Building Construction, ASCE Press, American Society of Civil Engineers, Reston, Virginia 1997 (Readily available by interlibrary loan from Memorial University, Newfoundland)  (Note: This study did not include failure at the foundation or basement level)
  6. Swinton, Michael C., NRC-IRC and Kesik, Dr. Ted, University of Toronto,    Performance Guidelines for Basement Envelope Systems and Materials, 185 pg, Research Report 199, National Research Council, Canada October 2005


Can you “calibrate” a forensic expert?

What happens when we calibrate something, and can the procedure apply to a person?  For example, a forensic expert?  Does it happen unbeknownst to an expert?

I said in a recent blog that this happens to an expert when he visually examines the site of a failure or accident in the built environment – he gets calibrated to the site. (Ref. 1)

Then I began to think about it.

This description of a visual examination came to me when I remembered hearing years ago about an American engineer asking to have some pits dug at a site that he was visually examining in Newfoundland, so he could “…get calibrated to the site”.  The phrase resonated with me at the time.

This was George F. Sowers, a professional engineer with an international reputation in foundation and geotechnical engineering. (Ref. 2)  All of us in this field of practice knew of him.  This was a serious foundation problem if Dr. Sowers was called in.

Still, I thought, I better check the meaning of calibrate in the event Dr. Sowers stretched it a little.

The Merriam-Webster dictionary gives several definitions of calibrate, one of the last in a list of five is most applicable to Sowers use of the word:

“…to adjust precisely for a particular function, e.g., calibrate a thermometer”

Sowers was getting himself adjusted precisely to the site so he could function in a particular way – as the forensic engineer investigating the cause of the problem at this particular site.

You might say this is wandering away from a dictionary’s meaning. (Ref. 3)  I don’t think so.  One thing I’ve learned blogging on the nature and methods of forensic engineering in the past eight years is that words are taking on new shades of meaning all the time.

Using the word calibrate in a recent blog to describe what happens during a visual site assessment just came out of me from deep down inside.  It was natural.  Also knowing it was used this way by a quite reputable and experienced engineer years ago.  And it’s supported by Merriam-Webster.

The word calibrate does suggest preciseness, and that’s a big element in a visual assessment of a site – you can’t plan a forensic investigation of a failure or accident until you’ve seen the site.  Think, a picture (seeing something) is worth a 1,000 words.

Can you “calibrate” a forensic expert?  Yes.  It happens as a matter of course when s/he does a visual assessment of a site before commenting on how to determine the cause of the accident or failure, if more investigation seems necessary.


  1. COVID-19 and an initial forensic task aka a visual site assessment, sans social distancing.  Posted June 1, 2020
  2. Sowers, George F., Introductory Soil Mechanics and Foundations: Geotechnical Engineering, 4th edition, MacMillan Publishing Co., Inc, New York
  3. Family Word Finder, A New Thesaurus of Synonyms and Antonyms in Dictionary Form, 896 pg. Reader’s Digest in association with Stuart B. Flexner 1975




Conferring on video with apps like Zoom: Another forensic tool

Video conferencing with apps like Zoom makes it even easier to push back against COVID-19 and do the right thing at the start of a forensic investigation.  That is, get on site quick-smart after a failure or accident and do a visual assessment.

An app like Zoom comes into the picture when the forensic expert is briefed on the incident during a video conference.  And what a marvelous way to get briefed – sitting in a bright and colourful virtual meeting room.

Microsoft Teams (‘Teams’) and Go To Meeting are two other video tools making life easier and cost effective.


I knew about Zoom but only just.  I learned more last Wednesday evening (June 3) when I took part in a virtual meeting with members of CATAIR, the Canadian Association of Technical Accident Investigators and Reconstructionists.  Of course it was like sitting and meeting in the same room as many of you know.

CATAIR provides accident investigators a professional and affordable way to meet and share experiences and ideas.  The association consists of serving and former police officers as well as professional engineers and others with a technical background.

The purpose of the meeting on Wednesday was to discuss organizing regular meetings of the Atlantic chapter of CATAIR as video conferences.  Also supplemental “get togethers” to discuss reconstruction topics and, generally, to stay in touch.  In the past we met in person in Amherst, Nova Scotia and Moncton, New Brunswick.

My interest in Zoom was tweaked.  A little more checking and I concluded video is going to play a big part in forensic engineering investigation in the future – starting with the initial briefing.


It’s big in the corporate world now.  More than half the Fortune 500 companies confer on Zoom video regularly.  Almost all the top 200 US universities do.  And that was the case before COVID-19 shut everything down.  After the lock-down is lifted many will still be working from home and conferring on video.

One of my three daughters oversees computer support for a testing laboratory with five divisions at a large hospital in Toronto.  She virtually meets with staff on video throughout the day using Zoom.  Another daughter in Edmonton works from home for a university and often relies on Zoom to connect.  My third daughter practices vet medicine in North Berwick, Maine.  Hopefully she relies on video conferencing – anything to stay clear of the COVID-19 epic centre in New York, in a sense, just down the road from her.


Connecting on video is enhancing our lives socially as well.  My neighbour connects with his two daughters out west weekly courtesy of the Zoom app.  One of the chaps who took part in Wednesday’s virtual meeting and his partner catch up with their family on video as well.  Guess who is going to be “meeting” with his daughters when he gets up to speed with Zoom?


There’s no question conferring on video using apps like Zoom is going to impact forensic engineering investigation.  For sure during COVID-19 but afterwards as well.

Forensic experts can be briefed on video now about a failure or accident so they can get on site before the dust settles and do a visual assessment.  The tools are there to be used.

This type of simple, cost effective assessment is sometimes all that is necessary.  If more forensic work is necessary, meeting during a video conference to report progress is certain to ensure continued savings.






COVID-19 and an initial forensic task a.k.a a visual site assessment, sans social distancing

Like mine, your work has possibly slowed a little because of COVID-19.  For that matter, I’m sure most practices and vocations.

However, we can and should follow through on one forensic task: An initial visual assessment of a failure or accident site, as soon as possible after an incident.  It’s just as important during COVID-19 days and just as easy.

This is also a forensic task that quite often is all that is necessary in determining probable cause, and quite often, cost effective in the extreme.

It’s also important to be seen to have done this by the parties to a dispute or claim.  It’s easier to explain doing too much than too little.  COVID-19 would not cut it as an excuse for not getting on site as soon as possible.

COVID-19 is not a good reason because an initial visual site assessment is carried out by the forensic expert alone. Social distancing is not a problem when you’re walking around a site by yourself doing things like the following:

  1. Noting the features in the terrain, in general, or on the site, in particular, relevant to the accident or failure,
  2. Examining the exposed surfaces of the failed structure and how it was initially constructed and it’s condition now,
  3. Measuring the parts of the structure or component that failed,
  4. Examining the surface where the victim slipped and fell,
  5. Taking terrestrial and aerial photographs and video, and, generally,
  6. Getting calibrated to the site.

Neither is social distancing a problem when taking a briefing by phone, e-mail or Zoom.  Nor reviewing documents sent by courier.


I recently looked at e-mailed photographs of the scene of a slip and fall.  The probable cause was known but not who was responsible.  I was able to identify from the photographs the three investigative tasks needed for determining responsibility.  One task was getting some accurate measurements on site – rough ones were possible from the photographs – plus getting that calibrating visit under my belt.

But, as I type this, it occurs to me that one of the other three tasks could be carried out in a very preliminary way and indicate probable responsibility.


However, we do need to get on site quickly after an incident because physical and environmental conditions change and important data can be lost.  This is the case whether it’s a breaking-news, catastrophic failure or a tiny component failure, a terrible accident or a seemingly “simple” slip and fall.  Examples of important data include:

  1. The volume of oil in the ground and the ground water after a fuel oil spill; (the change in volume depends on subsoil conditions and the topography)
  2. The location of the plume of contamination on the water table – think, a pool of oil in the shape of a feather with the big end downstream; (the location changes, sometimes very quickly, and this is important data)
  3. The condition of the floor surface at the location of a slip and fall accident; (this can change quickly)
  4. The height of flood water; (changes very quickly)
  5. Weather conditions after a crane collapses or a bridge fails; (this changes quickly but micro weather records sometimes exist)
  6. The size and configuration of cracks in a wall; (these features of a crack can change fairly quickly and often get worse)
  7. Tidal conditions at the location of a seaside structural failure; (changes cyclically)
  8. Sagging floors in a building; (are they sagging more?)
  9. Foundation conditions causing a building to vibrate; (these conditions change seasonally when they’re causing a problem)

Often, as indicated above, an initial visual assessment can point confidently at the probable cause of a failure or accident.  For example:

  1. I knew why a gabion wall failed on the coast as soon as I saw it, and it wasn’t coastal erosion (a gabion is a wire basket filled with rock)
  2. I also knew why a building vibrated in the winter as soon as I saw the sloping site and how the foundations were constructed
  3. The cause of a slip and fall accident on a wet floor in a dry sauna came to me on the drive back to my office – and where the water came from – after visually examining the site
  4. I knew why a furnace oil tank collapsed into a trench spilling oil everywhere based on a virtual visual site assessment – a study of site plans and photographs taken by others (I wasn’t permitted to go on site nor even drive the road nearby)

And if a more detailed and intrusive investigation is needed – none was in the bulleted examples above except skid-resistance testing on the slippery sauna floor – then the visual site assessment ensures more investigation is well planned.

For sure, COVID-19 might delay additional investigation till the lock-down was lifted –  but it can’t delay a visual site assessment by a lonely forensic engineering expert.  

How I got good forensic video in the spring, and you can too

I’m learning all the time – see below – about new methods of forensic investigation.  Also, hopefully, for my readers, increased understanding of the nature of expert work.  For example, aerial video from a drone has been a real eye-opener for me and some of my clients in recent years.

It struck me recently while walking my dogs in a forest that spring is a good time for taking aerial video during a forensic investigation.  For sure, fall as well.  You see through the leafless trees to a forest floor brightly lit by spring sunshine.  I can see my dogs off at a distance in the leafless forest why not the forest floor from above?

Even as I draft this blog I’m learning.  It occurs to me that a cloudy day would be even better – no shadows to confuse what you’re seeing on the ground.  A hardwood forest is best, of course, after the leaves have fallen.

For example: I flew over a leafless forest last spring during a site assessment case and got excellent aerial video.  You could clearly see a piece of gravel the size of a golf ball from 100 to 200 feet up.  The video was a dispute-resolution maker.

To be upfront with you though, it was seeing my dogs running in the forest that made me realize why I got good video last spring.

Another example: I had another case, a fuel oil contaminated site, that was in a dense hardwood forest that was a prime candidate for this type of aerial video.  It didn’t come to pass – the case went off on another tack – but I was ready to capture good video through a leafless forest.

Aerial video of fuel oil contaminated sites has been a game-changer for me in treeless terrain so why not in leafless terrain?

Why am I telling you this?  Because, if you’re processing a dispute or claim that involves an accident or failure in the built environment now is the time to get aerial video of the site.  If there are leafless trees on or near the site, go aloft now.  COVID-19 is no problem because it’s easy to keep your distance outdoors.