Fifty investigators are probing a fire at a Canadian military base that killed four soldiers and injured 39 others, Prime Minister Mark Carney said Monday, amid mounting questions as to why training proceeded despite officials' awareness that a fire was burning nearby.

Addressing Parliament in Ottawa, Carney stated that the Canadian Forces National Investigation Service was spearheading the investigation — with the support of the Royal Canadian Mounted Police — into Saturday's tragedy at Canadian Forces Base Wainwright in Alberta.

Lawmakers observed a moment of silence prior to Carney's addressing the House of Commons; opposition party leaders likewise paid tribute.

“A fire was raging within the training area.

Propelled by ferocious winds, it traversed nearly a kilometre in under a minute, reaching the very spot where soldiers had assembled,” Carney said.

He stated that investigators had yet to ascertain what had ignited the grass fire.

“We will get the answers to what caused this terrible tragedy, as expeditiously and transparently as necessary,” Carney later told reporters.

The fire overran soldiers of the 3rd Battalion, Princess Patricia’s Canadian Light Infantry, together with Army reservists engaged in live-fire training.

As of Monday, nineteen of the injured remained in critical condition.

Conservative opposition leader Pierre Poilievre, who represents Wainwright in Parliament and was visiting the town, said many had sustained severe burns necessitating weeks or months of intensive care.

He cautioned that their lives might never be the same.

Maj. Gen. Wade Rutland stated on Sunday that military officials had been aware of the fire for hours but had believed it to be contained, permitting training to proceed until the winds abruptly shifted.

Some 84 soldiers of Charlie Company were undergoing training at two locations — one given over to grenade throwing, the other to rehearsing assaults upon simulated enemy positions.

The fire swept into the latter area.

Carney stated that the soldiers were making preparations for a mission the following spring aimed at reinforcing Canadian troops serving with NATO in Latvia.

Rutland stated that investigators would ascertain whether winds had propelled the flames toward the soldiers or whether the fire had spread undetected through the vegetation.

They would likewise examine whether military safety protocols require revision.

The military identified the deceased as Sgt. Morgan Wong of Edmonton; Pvt. Shaun Farrell of Prince Albert, Saskatchewan; Pvt. Aidan Goulding of North Vancouver, British Columbia; and Pvt. Hayden Lykkemark of Langley, British Columbia.

Carney recalled Goulding as an individual who readily embraced formidable challenges, and Wong as someone upon whom his family could invariably rely.

He characterised Farrell and Lykkemark as the closest of friends, noting that Lykkemark had harboured aspirations of a career in law enforcement.

Poilievre recounted having encountered Goulding amid Canada Day festivities at the base in July, when a contingent of young soldiers approached him requesting a photograph.

In the aftermath of Saturday's tragedy, someone forwarded him the picture identifying Goulding as among those killed.

Poilievre further recounted having heard testimonies of soldiers who charged toward the flames to aid their comrades, characterising their conduct as extraordinary feats of courage.

Military liaison officers were rendering assistance to families at hospitals across Edmonton, Calgary, Red Deer and Wainwright, while mental health teams and chaplains were likewise furnishing support to soldiers and their families.

Carney directed that, on Sunday, flags be flown at half-staff atop every federal building nationwide in tribute to the four soldiers killed.

Flowers were laid at Wainwright's century-old war memorial—a stone clock tower commemorating soldiers fallen in bygone conflicts—which withstood the devastating conflagration that ravaged downtown Wainwright in 1929.

“They were training to defend Canada. To serve Canada. Now, Canada serves them,” Carney said.