Firefighters fight a blaze at Hardcore Auto Clinic in Edmonton on Monday. ((CBC))

Firefighters faced a dangerous challenge while extinguishing a blaze that caused extensive damage to an autobody shop in north Edmonton on Monday.

Investigators are trying to determine the cause of the fire, which broke out shortly after 6 p.m. at Hardcore Auto Clinic at 126th Avenue and 133rd Street.

The fire, which started on the main floor and spread to the roof, burned for an hour before it was bought under control, a task complicated by the volatile liquids in the shop.

"You'll have paints, you'll have thinners, you'll have acetylene and oxy there," fire Capt. Bill Quinn said. "Every one of them poses a risk to our units."

To minimize that risk, the firefighters spoke to the owner to find out where the volatile liquids were kept and tried to keep the area "quenched and cooled," Quinn said.

"Everything is a calculated risk," he said.

Firefighters succeeding in stopping the volatile liquids from igniting, he said.

No one was in the building when the fire started and workers removed a number of vehicles from the shop to minimize damage, but the building has been reduced to a burned-out shell.