Quebec's Order of Engineers has decided not to lay blame for the 2006 De la Concorde overpass collapse because too much time has elapsed to properly investigate.

Five people died and six were injured when part of the Laval overpass collapsed on Sept. 30, 2006.

A public inquiry was launched shortly after the incident. The Johnson commission concluded that a "chain of causes" spanning 35 years was behind the collapse, but no single person or group could be held responsible. 

However, the commission recommended that the companies and managers of Desjardins, Sauriol & Associés, Inter State Paving Inc. and Acier d'armature de Montréal Ltd. be held responsible for the De la Concorde overpass collapse.

"We now know that nearly 40 years ago, there was negligence on the construction site of the de la Concorde overpass, and lapses in the managing of the structure throughout its useful life," the Johnson report from 2007 stated.

11 of 12 complaints dismissed

De La Concorde overpass

Quebec's Order of Engineers has decided to not hold any of its members responsible for the 2006 De La Concorde overpass collapse. (Radio-Canada)

Chantal Michaud, trustee of the Quebec Order of Engineers, said it's difficult to lay blame because so much time has passed since the construction of the overpass in 1970. Michaud said certain documents cannot be found and that some of the engineers are dead. 

Documents obtained by Radio-Canada indicate that 11 of the Order's 12 investigations into some of its members who were involved with the overpass have been dismissed. No one was found to be at fault.

The last remaining case is related to a minor administrative offence.

However, other documents obtained indicate blame will be laid in the case of the Viger Tunnel incident of 2011 in which a 25-tonne concrete slab crashed down onto the road below.

Complaints against the consortium responsible for the tunnel's construction — Cima+, Dessau and SNC-Lavalin — will be filed in the fall.