Welding led to deadly explosion at Quebec propane company last January: safety board

Quebec's workplace safety board has concluded that a deadly explosion at a Quebec fuel distributor this year could have been avoided had proper safety procedures been followed.

The Jan. 12 blast that killed three workers occurred as a welder was repairing cracks in a tank trailer, the board, known as the CNESST, said in a report released Tuesday.

Fuel distributor Propane Lafortune of St-Roch-de-l'Achigan, Que., and welding contractor Soudure AC should have done more to ensure the tank trailer was completely empty of fuel before welding began, the report concluded.

"The physical cause of the explosion was the ignition of gasoline vapour inside a tanker compartment, which caused the explosion, followed by a building fire," board inspector Martin Rondeau told reporters in Joliette, Que.

The fact the work was being done inside a garage rather than outdoors contributed to the risk of explosion and death, the investigation found.

Board inspector Annie Lepine said the tank trailer had been deemed unroadworthy by Quebec's automobile insurance board. The welding work had begun outdoors in the town about 50 kilometres north of Montreal on the day before the explosion, she said. However, due to the complexity of the job, the welder wanted to get under the vehicle.

One of the owners of Propane Lafortune suggested the welder use a pit intended for vehicle repairs inside the company garage, Lepine said, noting the garage shared a wall with the company's office.

The next day, the trailer was brought inside and work continued. Lepine said the owner of the welding company was present at the beginning of the day and was involved in planning the work, but he had left by the time of the explosion.

At around 11:15 a.m. an explosion occurred, Lepine said. The blast and ensuing fire killed the 26-year-old welder, Christophe Paradis, and two secretaries working in the office, Celine Pilon, 65, and France Desrosiers, 65.

The trailer had delivered its final load of fuel before being taken off the road, Lepine said, but between five and 10 litres can remain in each tank after delivery. The trailer that exploded had six tanks.

Rondeau said that before the repairs began, the tanks should have been cleaned and checked with tools that detect the presence of gasoline vapour. Because vapour is heavier than air, working in a garage pit increased the danger, as the vapour would sink to the location of the welder.

Many of the safety measures that should have been taken are in the National Fire Code, which forbids working on tanker trucks indoors except in specially constructed facilities, Rondeau said. He said the goal of the CNESST report is to determine what should be done to prevent similar tragedies from happening.

"There were things that weren't done that day, of course, but what we presented is what should have been done and what should be done in the future," he said.

The CNESST said its legal department is analyzing the inspection report to determine whether the board should issue fines.

Gaston R. Lafortune Inc. said in a written statement it is aware of the CNESST report and has been working with the board since the incident in January.

"More concretely, we are finalizing, again in collaboration with the CNESST, the development of safe work procedures that will be enforced for all work on our tanks. We reiterate our most sincere condolences to the families and loved ones of the deceased," the company said, adding it would not comment further.

- This report by The Canadian Press was first published on Dec. 19, 2023.