MONTREAL - Transport officials in Quebec now have a theory as to why a massive chunk of concrete fell from the Viger Tunnel and smashed onto the Ville-Marie Expressway.
"Workers were removing concrete from the walls of the tunnel during repairs," said Daniel Bouchard, a structural expert from the Transport Ministry. "But it's believed they removed too much. Immediately after, the beam fell."
In a press conference Wednesday, Transport Minister Sam Hamad insisted investigators will get to the bottom of who is responsible for the collapse.
"We have to put out many questions and say, ‘What has happened? Can we do better than what we did?'" he said.
Workers have removed the last of the debris from the 25-ton chunk of concrete in the tunnel, and large sections of concrete have been transported to a secure site for further study.
Structural engineer Hellen Christodoulou said the government's preliminary assessment is feasible, but simplistic and doesn't reveal whether or not the Transport Ministry did all it could to prevent the collapse.
"The first question before assessing what damage occurred and how it occurred is to see which recommendations were done -- and out of those outstanding ones, (which) would probably have had a contributing factor to what happened," said Christodoulou.
A 2008 engineering report released this week warned the tunnel was in a "critical" state and had become dangerous to users.
The government said it followed some recommendations in that report, but has not completed the work.
Hamad said risk management is the concern of private companies – the contractors, on-site technician and supervising engineers were all employees of private companies.
"We do a (public-private partnership) for (Highway) 25, a PPP for the 30 -- it's done by private engineers, private contractors, but they take the risk, they manage the risk and if there's any problem on that, they're responsible," said Hamad.
Christodoulou disagrees, arguing that when it comes to public safety and the public coffers, the government is responsible.
"The custodians are the ministry and I would imagine they would know that better. They would have the responsibility to make sure that all these firms that are being hired are doing exactly what they're doing," she said.
Hamad said he hopes the tunnel on the Ville-Marie Expressway can reopen by Monday, when Quebec's construction holidays end and traffic in Montreal will become far busier than it has been in the last two weeks.
