Flames that killed four Canadian soldiers and left 19 people in critical condition began with a smoldering grass fire that quickly grew in an Alberta base's training area where personnel were carrying out exercises, officials said on Sunday.
Officials said 39 people were in hospital as a result of the fire at Canadian Forces Base Wainwright, which Prime Minister Mark Carney described as one of the worst peacetime tragedies for Canada's military on home soil.
Winds up to 96 kilometers (60 miles) per hour fed the blaze which began around 4 p.m. MDT (2200 GMT) on Saturday. But they were below 50 km per hour leading up to the fire, Major General Wade Rutland told reporters at a news conference.
He described the sudden high winds and resulting spread of the fire as an "uncommon, rapid" event in which the flames advanced 1 km in 30 to 60 seconds.
"I’ve certainly never seen anything like it," said Rutland, commander of 1st Canadian Division, which is based in Edmonton, about 210 km west of the military site.
Officials identified the dead as Sergeant Morgan Wong, Private Shaun Farrell, Private Aidan Goulding and Private Hayden Lykkemark.
"The nation is in mourning for those brave members of our Armed Forces whom we have lost," Carney said Sunday, adding that he had ordered flags on federal buildings across the country to be lowered to half-staff to honor the victims.
Alberta Premier Danielle Smith said many of the injured will require "weeks and months" of specialized, intensive medical care.
When the fire began, Rutland said, 85 soldiers from the 3rd Battalion, Princess Patricia's Canadian Light Infantry, were in "high intensity" combat training using live munitions at the base, which is located in a prairie setting. The soldiers were preparing for deployment to Latvia, where Canadian forces currently have their largest international military operation.
Rutland said the incident remains under investigation and declined to speculate on what caused the grass fire. Officials do not believe the region's extensive oil and gas infrastructure had anything to do with the incident, he said. He also ruled out "outside interference."
CFB Wainwright had 1,310 military and civilian personnel stationed there as of 2021, according to census data. The base houses the Canadian Manoeuvre Training Centre, which runs training scenarios and exercises for the army. Carney said those affected in Saturday's fire came from military bases across the country.
Military and civilian firefighters fought the fire through the night in "some of the worst conditions imaginable," Carney said.
Twenty-two ground ambulances and eight air ambulances responded to the scene, Smith said. Patients are being treated in Edmonton, Wainwright, Calgary and Red Deer.
Military search and rescue technicians also parachuted into the site, Rutland said.
Health staff in Edmonton said a "code orange," or mass-casualty event, was declared to coordinate the medical response for patients being transported from Wainwright.
The town of Wainwright, with a population of about 6,600, is just north of the base.
The municipality posted on social media that the fire had crossed the base fence into the nearby district but no evacuation orders had been issued. It said on Sunday that the fire is not expected to spread beyond its current boundaries.