De la Concorde Overpass collapse

The De la Concorde overpass collapse occurred at a bridge over Quebec Autoroute 19 near Montreal, Quebec, Canada, at midday on September 30, 2006. On that Saturday, around 12:30 pm, the center section of the south lane of an overpass (65-foot or 19.8-metre section of a three-lane overpass) collapsed in Laval, a suburb of Montreal, on Boulevard de la Concorde running over Autoroute 19. The collapsed section crushed two vehicles under it, killing five people and seriously injuring six others who went over the edge while travelling on the overpass. The north-lane half, along the same bridge, did not collapse. The autoroute was closed for almost 4 weeks, "disabling an important north-south link between Montreal and its northern suburbs as well as the Laurentian region".

A number of people had noticed that the overpass was not in good shape:

When the Quebec Ministry of Transport was contacted regarding blocks of concrete falling onto Autoroute 19 from the Concorde Boulevard overpass above, a patroller was sent to do a sight and sound test to gauge whether the road should be closed and to clear away the concrete hazards; this was 30 minutes before the collapse. Neither roads were closed as the official concluded that the bridge presented no immediate danger. The patroller however did demand that an inspection be carried out as soon as possible, but was told "that an inspector would show up only on Monday, two days later".

The Ministry also sent out messages to journalists and traffic reporters warning of the concrete debris; this was confirmed by Josee Seguin, a spokeswoman for the Ministry.

The overpass on the Boulevard de la Concorde (Concorde Boulevard) was built in 1970 and was expected to have a life span of 70 years, of which it only lasted 36. David Lau, as part of an article for the Ottawa Citizen, suggests that this estimation of 70 years was inaccurate. They underestimated traffic volumes; they also did not take into account that "the amount and weight of trucks [on] today's roadways are significantly higher". He noted, "30 or 40 years ago, engineers could not anticipate the traffic some of their bridges would be forced to accommodate in the coming decades".

The design of the overpass was considered innovative at the time; however, this design made it nearly impossible to inspect thoroughly, as the entire deck would have had to be removed for such an inspection.

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Wikipedia