Three employees in Blainville, Quebec, were killed Wednesday after a giant tank of compressed air exploded while they were preparing a vehcile for safety tests.
Two of the men were decapitated in the powerful explosion of the 1,500-kilogram tank at PMG Technologies, said Albert Stringer, Blainville's director of public security.
"There were even bits of the vehicle that reached the ceiling. I haven't seen an accident like this in the 21 years I have been here," said Stringer.
The men were engineers and technical assistants who worked at the plant, which tests vehicles to comply with federal safety standards.
Officials at a news conference said that the explosion was caused by compressed air.
Three men were in the process of using it when the tank exploded, Stringer said.
Company vice-president Gilles Marleau refused to say what caused the blast or whether a tank exploded.
Marleau said up to eight people were treated for shock at a hospital in nearby St.-Jerome, but Stringer said the number was closer to 20.
The company, which has 50 employees, used to be the site of a Transport Canada facility. The plant has been privately owned since 1996.
Marleau said he did not know whether the company would suspend activities.