Downtown underpass in Montreal drops 25-tonne concrete beam

A massive 16-metre chunk of concrete fell off the roof at the entrance to the Ville-Marie Expressway tunnel in downtown Montreal on Sunday, July 31.

The 25-tonne slab fell onto the roadway below in a section of the road near Saint-Urbain, not far from the convention centre, known as the Palais des Congrès. Fortunately no-one was injured since it was during a public holiday. 

However, the debris closed the eastbound lanes for over a day until engineers could ascertain that the rest of the structure was safe.

Early reports said the concrete segments that fell was a part of the structure designed to reduce glare for drivers as they enter the tunnel.

Over 100,000 vehicles use the downtown Ville-Marie expressway on the average weekday. On August 2, the CBC reported on a survey of 700 Montreal commuters found that 60% of them were afraid to drive under an overpass, and 50% were afraid of driving over the city’s bridges.

The incident quickly roused fears about the state of the province’s aging infrastructure. The Ville-Marie Expressway was built in 1972.

In particular it woke memories of a similar incident in 2006 when a portion of the De la Concorde overpass fell onto Autoroute 19 in Laval and killed five people travelling in a car below.

The province held an inquiry known as the Johnson Commission after the Laval overpass collapse.  It found that the problem with that 40-year old structure was due to its unique design that required special inspections that were not carried out. It also found that it was constructed with poor quality concrete and that there had been inadequate site supervision during its construction.

See article on Johnson Report: https://www.canadianconsultingengineer.com/news/commission-reports-on-causes-for-laval-overpass-collapse/1000070771/