Prime Minister Mark Carney confirmed earlier Sunday that four service members were killed in the blaze and declared a period of national mourning, calling it one of the worst peacetime tragedies for Canada's military on domestic soil. While early military source reports indicated a live round hit a natural gas well or line on the base, Global News later reported that preliminary findings suggest a munition from the live exercise sparked a grass fire that led to an explosion and was pushed past the base perimeter by winds up to 100 km/h (62 mph).
The influx of burn victims overwhelmed local medical facilities in Wainwright, prompting the military to parachute personnel into the local medical center and transport patients via at least three helicopters and four fixed wing aircraft to larger cities. A doctor at Royal Alexandra Hospital in Edmonton told CBC News that regional hospitals mobilized for what he called a "one in every 15 to 25-year disaster."