How a grass fire at a Canadian military base killed four soldiers

A grass fire at Canadian Forces Base Wainwright in Alberta killed four soldiers and injured 39 people, 19 critically. The fire appeared contained enough on Saturday morning for live-fire training, but the wind shifted and flames travelled one kilometre in 36 seconds, according to Major-General Wade Rutland. The cause of the blaze remains unknown. Prime Minister Mark Carney called it one of Canada’s worst peacetime military tragedies on domestic soil.