Brigadier-General Vanessa Hanrahan, commander of the Canadian Forces Military Police Group, told reporters on Thursday that the deadly fire began on a grenade launcher range during military exercises on Saturday. High winds carried the blaze across the base, she said, and "a subsequent change in wind direction and velocity significantly increased the fire's intensity."
The flames spread to a training area at the Wainwright military base in Alberta. Because the fire was in the "permanent danger area" of the range, firefighters were unable to directly combat it, Hanrahan added.
The fire swept through on Saturday afternoon during high-intensity combat training involving Charlie Company of the 3rd Battalion, Princess Patricia's Canadian Light Infantry. About 84 soldiers were split between a grenade range and an area where they practised attacks on simulated enemy positions.
Four soldiers died and 39 were injured, with 27 requiring hospitalisation, in what officials described as one of the worst peacetime tragedies for Canada's military. The soldiers and reserve members were exercising ahead of a planned deployment to Latvia, where Canadian forces run their largest international military operation.
The Wainwright base is one of the largest operated by the Canadian Armed Forces and regularly hosts training exercises involving NATO personnel. During the final months of World War II and for several months in 1946, it served as an internment centre for German prisoners of war.