I have been watching the following through the window at work. I even took photos, you’ll have them when I get home!
Friday, August 24, 2007
Hundreds of people were evacuated from the downtown McGill metro station this afternoon and a one-block section of de Maisonneuve Blvd. was closed to traffic after gaping cracks appeared in the ceiling of Montreal’s famed underground city.
Fearing the road would collapse, engineers shut down the metro’s green line, evacuated nearby buildings and cordoned off the roadway creating traffic chaos in the city center.
The underground city around The Bay department store was evacuated as well as the basement and first floor of the department store.
“We were worried that if the road collapsed it would cause a shock wave that would flow into The Bay,” Gilles Ducharme, chief of operations for the Montreal Fire Department, said.
He said engineers from the city, Hydro-Quebec and the transit commission were evaluating the cracks.
He said he had no idea how long the evaluations would take, what caused the cracks or when the metro and roadway would be reopened.
“The cracks may have happened just today or they may have been there for a few days,” he said.
“If they have to shore up the road it could take days, maybe all of next week.”
Firefighters were called to the underground mall and metro at 1:30 p.m. after employees working for The Bay discovered water leaking through the ceiling of the underground mall.
Their concern turned to panic when they noticed a large crack had formed along the ceiling under the north side of de Maisonneuve.
“It looked like the ceiling had fallen about one inch,” Ducharme said.
Prof. Saeed Mirza, a McGill University structural engineer, said the engineers likely will have to excavate the road in order to thoroughly assess the problem.
“A one inch displacement is very serious,” he said.
He noted that the mall is only about 40 years old.
“This kind of problem should not have occurred,” he said.
“I have noticed cracks in other metro stations at Peel Street and the Bonaventure station,” he said.
“Usually this isn’t a problem unless you don’t have steel reinforcement.”
The city has recently used large jackhammers and heavy equipment to excavate part of the city block behind The Bay to construct a bicycle path along de Maisonneuve. But Mirza said this should not have caused the cracks.
“There’s plenty of heavy traffic going over this road every day,” he said.
The underground city drops two floors beneath the road with the shopping mall over the metro tunnel.
The ceiling of the first floor is about five meters below the road, Ducharme said.
Between the road surface and the mall are layers of asphalt, concrete, aggregate and then concrete girders sitting on support posts. There are also water pipes, gas lines and electrical wiring between the road and the mall.
Mirza said one possible cause is that earth between the roadbed and the mall may have shifted.
“Or it could be a structural problem that goes right down into the metro,” he said. “That would be very serious.”
© The Gazette 2007