India, Oct. 19 -- Four Canadian soldiers died and 39 others were hurt, 19 of them critically, after a rapidly spreading blaze engulfed troops during live-fire exercises at a military base in Alberta, authorities reported.

Maj. Gen. Wade Rutland told reporters in Edmonton on Sunday that commanders had been aware of the fire for several hours and judged it contained enough to let the exercises go on. Then the wind abruptly changed direction and pushed the flames toward the soldiers. He said a fire covering a kilometre in just 36 seconds is far from normal. A commander on site told him the troops went from seeing no flames to being surrounded in under a minute.

The fire began Saturday while Charlie Company of the 3rd Battalion, Princess Pa...