Three people are dead and three in a hospital after being overcome by toxic fumes at a mushroom farm in Canada's British Columbia province, police said.
Constable Holly Marks of the Langley Royal Canadian Mounted Police said the incident happened Friday afternoon when a group of workers entered a utility shed at Farmers Fresh Mushrooms in Langley.
Other workers who came to the men's aid also were overcome.
Two of those hospitalised are were in a critical condition, the third stable.
Police were not sure what the fumes were.
Dozens of firefighters, emergency workers and a hazardous materials team were on the farm and RCMP said the deaths appeared to have been an accident.
BC's workers' compensation board is investigating.
Marks said the large farm was well kept - the operation consists of a large barn and several quonset huts (Nissen huts) and utility sheds.
The company provides mushrooms to outlets across Canada and California.