Quebec police open criminal investigation into fatal construction site collapse

MONTREAL — Police have opened a criminal negligence investigation into the fatal collapse of retaining walls on Tuesday at a construction site north of Montreal.

One worker died and two were injured, and a woman was treated for shock after the mobile office she was in fell into the excavated hole after the collapse in Blainville, Que.

Police identified the deceased worker as Alexandre Paris, 31, an employee of Preco-MSE, a Montreal-area firm that specializes in design and execution of deep foundations. The company offered condolences to the victim’s family, and offered psychological support to the employees affected by what happened.

“The employee was working as a specialized labourer for Preco-MSE, which is acting as subcontractor on the site where the accident occurred,” the company said in a statement released Wednesday by a public relations office.

“Another employee of the firm also sustained injuries, but his life is not in danger.”

Lt. Sara Tousignant of the Blainville police said an investigation is underway to determine if anyone is criminally at fault for the death. “We want to see if there was any kind of human error,” she said Wednesday.

Authorities received a call around 11 a.m. on Tuesday after the retaining walls of a building under construction gave way about 30 kilometres north of Montreal. Paris’s body was removed from the rubble later in the evening. It took several hours because the ground was deemed too unstable for emergency crews to access the site.

Syscomax, one of the firms leading the project, offered its condolences to the deceased employee. The site under construction is dubbed Project Liria, a mixed-housing build spread over 245,000 square feet next to Highway 15.

The project “involves several challenges, such as excavating the three-storey underground parking lot in complex soil conditions,” the company noted on its website.

Syscomax vice-president Jean-Philip Robitaille, reached by telephone on Wednesday, said all the company’s work sites are shuttered and employees have gathered at its headquarters in Mirabel, Que., north of Montreal. They are being offered psychological support.

“Our main focus right now is our staff and employees,” Robitaille said.

Robitaille said the company is co-operating with local police and provincial authorities. Preco-MSE said it is doing the same.

“At this point, it is too early to say what caused the accident,” Preco-MSE said.

Quebec’s workplace health and safety board, known as the CNESST, said its investigation is just beginning. “Two inspectors were dispatched (Tuesday) to secure the scene and gather information to find out the circumstances of this event,” said Émilie Marcotte, a spokeswoman for the agency.

“In addition, the CNESST has begun an investigation to identify the causes of the accident.”

Tousignant said part of Michèle-Bohec Boulevard will remain closed to traffic while city engineers determine if the road is safe.

This report by The Canadian Press was first published May 21, 2025.

Sidhartha Banerjee, The Canadian Press