Officials said 39 people were in hospitals as a result of the fire at Canadian Forces Base Wainwright in Alberta, which began around 4pm on Saturday, as winds up to 96km/h fed the flames.
Major General Wade Rutland described the fire as an "uncommon, rapid" event and said military officials knew about the fire for hours but believed it was contained before winds suddenly shifted, sending flames racing toward the soldiers.
"The fire was a kilometre away when the wind shifted. That is not normal for a fire to move a kilometre in 36 seconds," he said at a news conference in Edmonton.
Rutland said a commander at the scene told him soldiers went from seeing no fire to having flames upon them in less than a minute.
"I've certainly never seen anything like it," said Rutland, commander of 1st Canadian Division, which is based in Edmonton, about 210km west of the military site.
Rutland said the cause remained under investigation. He said the battalion was preparing for rapid deployment to global crises and a mission to reinforce Canadian troops in Latvia next northern spring.
Prime Minister Mark Carney said the fire was one of the worst peacetime tragedies ever for Canada's armed forces on home soil.
"The nation is in mourning for those brave members of our Armed Forces whom we have lost," Carney said on Sunday, adding that he had ordered flags on federal buildings across the country to be lowered to half-mast to honour the victims.
Alberta Premier Danielle Smith said 39 people were receiving medical care.
Sayeh Zielke, chief executive of Acute Care Alberta, said 19 were in critical condition, eight were stable and 12 were receiving treatment for less serious injuries.
Smith said some suffered severe burns and could face weeks or months of intensive treatment.
CFB Wainwright had 1,310 military and civilian personnel stationed there as of 2021, according to census data.
National Defence Minister David McGuinty said he would go to the city for briefings on the situation.
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.
Air ambulances from Edmonton and Saskatoon, which is about 300km from Wainwright, flew to the military base on Saturday, Carney said. Patients are being treated in Edmonton, Wainwright, Calgary and Red Deer, he said.
Health staff in Edmonton said a "code orange," or mass-casualty event, was declared to co-ordinate the medical response for patients being transported from Wainwright, CBC News reported.
The town of Wainwright, with a population of about 6,600, is just north of the base.
The municipality posted on social media the fire had crossed the base fence into the nearby district but no evacuation orders had been issued.
with AP
