Maj.-Gen. Wade Rutland, commander of the 1st Canadian Division of the Canadian Armed Forces, speaks to reporters at a news conference in Wainwright, Alta., on Sunday. (Kory Siegers/CBC) Details of the tragic fire that killed four service members and injured dozens at a Canadian Armed Forces base in Wainwright, Alta., on Saturday are still emerging as people mourn across the country.

Officials say 39 people were injured and taken to hospital, including 19 in critical condition, following a grass fire that broke out while soldiers were training at about 4 p.m. on Saturday.

The four soldiers who were killed have been identified as: Sgt. Morgan Wong of Edmonton; Pte. Shaun Farrell of Prince Albert, Sask.; Pte. Aidan Goulding of North Vancouver; and Pte. Hayden Lykkemark of Langley, B.C. All four served with the 3rd Battalion of Princess Patricia’s Canadian Light Infantry in Edmonton.

Prime Minister Mark Carney spoke from Ottawa shortly after noon ET, when he confirmed that four service members died and dozens sustained serious injuries. He called the incident "one of the worst tragedies for the Forces on Canadian soil in peacetime." Sources had initially told CBC News that seven people had been killed in the fire. Carney said Canadian flags would fly at half-mast at federal buildings across the country.

"The nation is in mourning for those brave members of our Armed Forces whom we have lost," he said. 'They will not carry it alone': Carney speaks on Wainwright tragedy 9 hours ago|Duration 0:33Multiple people were killed and hurt after a deadly fire at CFB Wainwright, a military base near Wainwright, Alta. Prime Minister Mark Carney said members of the Canadian Armed Forces were there to serve Canada — and now it's time for Canada to serve them. The prime minister thanked first responders and community members who have stepped up to offer their help.

"Canadians come together in crisis, that is the best of our country," he said. 'Uncommon, rapid' wind gusts Maj.-Gen. Wade Rutland, commander of the 1st Canadian Division of the Canadian Armed Forces, said at a Sunday afternoon news conference that a fire broke out during a high-intensity combat training exercise using live munitions.

Soldiers were throwing hand grenades on a grenade range at the time, he said, while others were in the section range doing a "section attack," where 10 soldiers attack a simulated enemy.

Rutland said it's not yet known what exactly caused the fire. "Quite frankly, it could have been any of that or none of it," he said. CFB Wainwright fire started during multiple training exercises 4 hours ago|Duration 1:59A lethal fire broke out at CFB Wainwright in Alberta on Saturday. Authorities say four members of the Canadian Armed Forces were killed and dozens more injured. Rutland said heavy wind gusts spread the blaze by a kilometre in less than a minute.

"This was uncommon, rapid, and I certainly hadn't seen anything like it," he said, adding that conditions for most of the day were "within standard procedures to conduct training exercises" with wind gusts below 50 km/h.

He told reporters that range control knew about the fire on the base for several hours, but it was decided that training "could carry on for a certain amount of time."

4 dead, at least 19 in critical condition after deadly fire at CFB Wainwright in Alberta Rutland said the fire swept quickly through to the area where the section attack was happening but noted the grenade range was not affected.

"I spoke to my commander last night, and he said within 30 seconds to a minute they saw no fire, and then there was a fire right on top of them."

Environment and Climate Change Canada issued a wind warning on Saturday for large parts of Alberta, predicting wind gusts of up to 90 km/h.

Flowers lie at the foot of the Memorial Clock Tower in Wainwright on Sunday. (Jennifer Gauthier/Reuters) A cold front moved through Wainwright between 3 and 4 p.m., shifting winds from southwesterly to northwesterly, CBC meteorologist Johanna Wagstaffe reported, at speeds hitting 69 km/h by 4 p.m.

In Edmonton, about 200 kilometres northwest, strong winds brought down trees and caused traffic signal outages on Saturday afternoon.

Rutland said how or if the fire might have spread without being noticed by those on the ground will be part of an investigation, and he emphasized that the military has "very strict safety protocols" for training exercises. Flags flying at half mast in Manitoba after deadly fire at Alberta military base Some witnesses said they heard explosions at the time of the fire, raising questions about whether oil and gas infrastructure at the site was hit, but Rutland said there is no indication that was the case.

The Department of National Defence told CBC News earlier that there were no indications that what unfolded at CFB Wainwright was the result of "any terrorist activity." Rutland said he expects a full investigation into the fire to take at least a month. 'Impossible-to-understand event' Wainwright Mayor Bruce Pugh said his community is closely interconnected with the nearby Armed Forces base, which is among the largest in the country. He said the incident would be seared in Wainwright's memory and that of its first responders and health workers.

"This will be an incident where it's a heartbreaking, impossible-to-understand event, but it's being met with an equal reaction of humanity," he said. 'We share our lives' with army members on base: Wainwright mayor 11 hours ago|Duration 1:22Multiple people have been hurt or killed after a fire at a military training area near Wainwright, Alta., on Saturday. Wainwright Mayor Bruce Pugh said the local hospital was acting as a triage centre, but that this is the largest mass casualty event the community has ever seen.

Federal Conservative Leader Pierre Poilievre, whose Battle River–Crowfoot riding includes Wainwright, said he's heard stories highlighting the courage shown by Canadian Armed Forces members and first responders during and after the fire.

"There are acts of courage that are almost unimaginable," he said. "People who ran towards rather than away from the danger and are now paying a cruel price, fighting for their lives in hospitals."

"Alberta's front-line heroes did not hesitate for a single second," Alberta Premier Danielle Smith said at Sunday's news conference.

In an earlier social media post, Smith said that the "loss of life and injuries are heartbreaking."

Firefighters continue to work on hot spots on Sunday after the fire. (Jennifer Gauthier/Reuters) Acute Care Alberta activated a "code orange" response for 10 hours to co-ordinate provincewide resources across health sectors. The provincial health agency said Emergency Health Services Alberta deployed 30 units to Wainwright: 22 ground ambulances and eight aircraft.

The response included support from service partners in Alberta and Saskatchewan.

Patients were transported from the Wainwright Health Centre to two hospitals in Edmonton, one in Red Deer and one in Calgary.

National Defence Minister David McGuinty said all levels of government have been co-ordinating in the response and lauded the actions of citizens, including Albertans who have stepped up to donate blood. "Federal, provincial and local teams are working as one," McGuinty said.

The entrance to CFB Wainwright is shown on Sunday. (John Ulan/The Canadian Press) 'Scene from a war movie' Brandon Simmons, a witness who said he lives in the Wainwright hospital's long-term care facility, told CBC's Jessica Campbell that nurses dropped everything as soon as the code orange was called, grabbing stretchers and gurneys, "any sort of chair that they could, any sort of medical equipment. And they were running it down to the emergency, to the front entrance there." Simmons said he saw people with burns being unloaded from military vehicles.

"I heard people screaming inside of those vehicles," he said. "You know, that will never end up being out of my mind.... It was just a scene from a war movie."