Tasks investigating the cause of a roof collapse

Specialists investigating the cause of a roof collapse like the one in Elliot Lake, Ontario, on June 23, 2012 might do some or all of the following tasks:

  1. Walk around and visually examine the collapsed structure from all angles paying particular attention to the structural elements, their location and condition.
  2. Photograph and film the entire collapsed structure from all angles including from a low flying plane or helicopter.  Include distance, mid range, and close-up sequences.  Also photograph and film the structure during the removal of the debris in the hunt for survivors.
  3. Photograph and film the structural elements where these are exposed to view.  Include close-up sequences.
  4. Interview witnesses of the collapse and occupants of the structure on different occasions prior to the collapse.
  5. Study photographs and videotape taken during the use of the structure.  For example, security camera records.
  6. Study photographs and film/videotape taken during construction of the structure.
  7. Review design of the structure paying particular attention to the structural design.
  8. Review the geotechnical investigation of the foundation soil, rock and groundwater conditions at the site of the structure.
  9. Review the construction drawings and specifications for the structure.
  10. Review the construction, and materials testing and inspection records.
  11. Review the as-built drawings.
  12. Review the structure’s maintenance records.
  13. Identify additional specialists needed to investigate aspects of the structure and the collapse.
  14. Schedule laboratory and field testing of materials used in construction.
  15. Schedule laboratory and field testing of structural elements of the structure.  For example, connections.
  16. Research the literature for similar roof collapses.
  17. Develop a model of the collapse including the progression.
  18. Analyse the data and formulate an opinion on the cause of the collapse.

The role of a professional engineer in counsel’s decision to take a case

Civil litigation tentatively begins when counsel meets with a potential client.  The purpose is to gather information to help him or her assess the merits of the case and decide if he should take it.

A professional engineer could have a role in this meeting, or in consultation shortly afterwards.  This is particularly the case if the legal and technical issues are likely to be complex requiring extensive engineering investigation to support a reliable opinion.

                 “I’ve seen cases that should never have gone forward …”

I’ve seen cases that should never have gone forward.  Not because of a lack of technical merit but because of the client’s limited financial resources to bear the cost of the forensic engineering investigation necessary to determine the cause of the problem.  These would be costs learned about after a claim was filed and discoveries held – and only after a professional engineer was retained to investigate the technical issues.

During the meeting, counsel obtains information from the client’s description of the problem and the damages he believes he has incurred, documents provided by the client, knowledge of witnesses, answers to questions raised by the lawyer, the lawyer’s past experience of similar matters, and comments by an expert on the technical issues.

One of several important considerations covered by the meeting and the lawyer’s review of the facts is the need for an expert on the case.  An expert can make or break a case and if thought to be necessary should be chosen carefully and retained early (Ref.1).  Even if only retained briefly to support counsel’s assessment of merit, in the event counsel decides not to take the case.

If a professional engineer is not included in the meeting, then counsel might confer with one later during his review of the facts prior to making a decision about taking the case.  The engineer would, of course, review the information from the meeting, particularly the documents, and identify the technical issues prior to counseling the lawyer.

The engineer can also provide very preliminary comment on the engineering investigation needed to address the technical issues and to formulate an opinion on the cause giving rise to them.  The engineer would educate counsel by outlining some of the tasks that would need to be carried out during an investigation and the time to do these – factors that can have a significant impact on the cost of litigation.

If the technical issues are complex – and the engineer can certainly help determine that, the monetary claim for damages likely to be substantial, and the lawsuit quite lengthy then this will affect the client’s litigation costs.  The client’s ability to bear these costs is important information in counsel’s decision on taking the case.  An engineer can have a role in assisting counsel make that decision.

Following are tasks that a professional engineer – or any expert for that matter, could carry out during or shortly after counsel’s first meeting with a potential client to assist counsel’s decision about taking the case:

  1. Attend and audit the meeting for technical issues, or meet with counsel shortly afterwards
  2. Review client’s descriptions of the problem and the reasons for claiming damages
  3. Read available documents
  4. Review witness’ statements as soon as taken by counsel
  5. Begin identification of potential technical issues
  6. Begin identification of technical documents counsel to seek
  7. Familiarize counsel on the typical stages and tasks in a forensic engineering investigation, the fact of unexpected follow-up investigations, the fact that investigations can lead in unexpected directions, the time required, and the difficulty estimating costs 
  8. Identify physical evidence, tangible exhibits and possible demonstrative evidence
  9. Brief counsel on parties that might be involved in the potential litigation and their relationship to the technical issues
  10. Provide information that would facilitate early settlement
  11. Note unfavourable evidence for the potential client’s claim
  12. Remind counsel that only one side of the story is known.  The opponent’s story and documents could give rise to a small shift in the technical facts and alter the complexion of the claim
  13. Tentatively assess the technical merits of the case with respect to the potential parties
  14. Outline preliminary engineering investigation and the major tasks involved
  15. Speculate on follow-up investigations
  16. Identify specialists that may be required
  17. Speculate on the order of magnitude of investigative costs
  18. If counsel decides to take the case, and position letters are appropriate, ensure that demand letters, and responses, are based only on well-established technical facts and data as known at the time


1. Stockwood, Q.C., David, Civil Litigation, A Practical Handbook, 5th ed, 2004, Thompson Carswell


Image credits, forensic engineering, and record rainfall

The tranquil sea coast in the heading is deceptive.

Many forensic engineering problems are caused by water or water is a factor in their cause.  J. Knoll photographed Prospect Bay, Halifax, Nova Scotia, Canada on a nice day.

Other days are not so nice along the 1,000s of kilometres of Atlantic sea coast – almost as long as Canada is wide.  Nor are the 1,000s of rivers and streams that flood – and they certainly have flooded this past June with the near record rainfall – 213 ml (8.4 in) at the Halifax airport compared to a normal 98.3 ml (3.9 in).

The rivers and lakes are still flooding as the land sheds the rainfall in runoff to our watercourses.  And the lakes are overtopping their banks – there are more than 4,000 lakes in Nova Scotia.  That’s just the water you can see on the ground surface.

There is also the groundwater, the water table, that you can’t see.  Water that is just below the ground surface or down deep, and fluctuating up and down all the time – certain to be well up and high after our rains in June.

Ground water flows through the ground much like a river flows on the land; welling up behind obstacles buried in the ground – e.g., foundations and basement walls, like river water wells up behind a boulder in a stream.

It’s been said that if you could take the water out of the ground, out of the soils and rocks beneath our feet, you would reduce foundation and ground engineering problems to a fraction.

The camera operator in the heading is filming the re-enactment of a fatal MVA from a sea king helicopter during a forensic engineering investigation.  I set up a full scale test site at Shearwater airbase complete with: 1. A traffic lane, 2. An obstacle in the lane, 3. A vehicle, 4. Monitoring devices to track vehicle behaviour on striking the obstacle, and, 5. Film crews to record the tests.

The sea and snow – frozen water, were factors in the fatal accident.

The surveyor in the heading is checking the adequacy of the underpinning of a structure during a forensic investigation.