Quebec’s workplace health and safety board, the CSST, has identified the causes of an explosion at a Côteau-du-Lac, Que. fireworks warehouse that killed two employees last year.

Nicole Brisson, 58, and Françoise Lacroix, 47, were killed on June 20, 2013 when a fire at the B.E.M. Fireworks warehouse on Highway 20 near the border of Ontario and Quebec caused an explosion.

Videos taken by witnesses show fireworks going off as the building burned.

The CSST ruled that workers were exposed to the dangers of fire and explosion as result of the following factors:

  • The use of electric equipment that was not in line with the standards of such an establishment.
  • The use of ferrous (iron) tools in the presence of explosives.
  • The presence of pieces of previously primed fireworks in the building.
  • A discharge of static electricity in the building.
  • A pyrotechnic device fell on the ground, setting it off.
  • Friction on a pyrotechnic device’s fuse caused the explosion.

In its report, the CSST pointed out some particularly egregious problems, namely that employees climbed wooden cases used to store fireworks to access higher levels of the factory.

The CSST said an employee could have stepped on a fuse, causing friction that may have set off a firework.

It also pointed out that fireworks are not supposed to be primed, much less stored, at a storage facility.

There were also two electric heaters on site that were deemed to be non-standard by an inspector in 2012.

B.E.M. Fireworks responds

Shortly after the CSST released its report, B.E.M. Fireworks issued a statement that said it acknowledged the recommendations put out by the workplace health and safety board.

"We will never know exactly what caused the accident last June 20," the statement reads.

However, the company denied that primed fireworks were in the building where the explosion took place. It also said the ferrous tools were not in the same section of the building as the fireworks warehouse and said the electric devices flagged by the CSST as non-conforming had not been in operation at the time of the incident.

B.E.M. Fireworks is a family business in operation for more than 40 years.

Read the whole CSST report (in French) here: