STM shuts down large portion of green line indefinitely after finding cracks in tunnel

The STM has shut down a large portion of the green line of Montreal's metro system indefinitely after finding cracks in the tunnel. A tweet from The STM around 5 p.m. said it shut down the line between Lionel Groulx and Frontenac for an "indefinite period" but did not explain why. A previous post said service would resume at 2 a.m.

The STM has shut down a large portion of the green line of Montreal's metro system indefinitely after finding cracks in the tunnel.

It's recommending people allow more time for travel on Tuesday.

A tweet from the STM around 5 p.m. Monday said it shut down the line between Lionel Groulx and Frontenac for an "indefinite period" but did not explain why. A previous post said service would resume at 2 a.m.

Shortly after, it clarified that a water leak had made it possible to detect cracks in the vaulted ceiling of the tunnel between the Berri-UQAM and Saint-Laurent stations following an assessment by its engineering team.

STM CEO Marie-Claude Leonard says unusual water infiltration was being monitored throughout the day.

Workers weren’t sure if it was caused by crumbling concrete or was part of a larger crack that would pose a safety threat, she said, calling the decision to close the stations a precautionary measure.

“The safety is our priority for our customers and our employees, and we need time to really know about the situation,” Leonard said in an interview.