A man died and three others were injured Monday when the snow-laden roof of a farm shed collapsed in Portage la Prairie in southern Manitoba, the RCMP said.

About 10 to 15 people were working in the shed, which houses vegetables, when a 24-metre section of the roof caved at about 3 p.m. CT.

Four people were unable to escape in time and were trapped by rubble. One managed to free himself, and firefighters were able to pull two of the others out alive.

The fourth person was recovered but pronounced dead at the scene.

The three survivors were sent to hospital, where two of them were treated and released. The third remains in hospital but is said to be in stable condition.

Police said the cause is being investigated, but early indications suggest the build-up of snow and ice on the roof triggered the collapse.

Rain that fell in the area all day, part of a weather system that swept through southern Manitoba, probably exacerbated the situation.

The shed is located on Mayfair Farms in the Island Park area.