A raging fire in a commercial marijuana grow-op forced the evacuation of part of downtown Squamish for a period of time Monday morning.

No one was hurt, and the fire was contained to the single warehouse in the 37000-block of Third Street.

"When we arrived on scene, the building was fully engulfed," said Squamish Fire Chief Bill Stoner. "We had heavy smoke coming out all sides of the building so we went on the defensive and it was probably two hours until we had it under control."

According to Stoner, smoke from the blaze did not smell like burning weed.

Please avoid the areas south of Vancouver Street in Squamish due to extensive hazardous smoke from a structure fire. <a href="https://twitter.com/hashtag/squamish?src=hash&ref_src=twsrc%5Etfw">#squamish</a> <a href="https://twitter.com/hashtag/FrontlinePolicing?src=hash&ref_src=twsrc%5Etfw">#FrontlinePolicing</a> <a href="https://t.co/1TiHbNnSSk">pic.twitter.com/1TiHbNnSSk</a> —@SquamishRCMP

"There were a lot of other things burning in that building as well," he said.

Huge plumes of dark smoke were seen billowing into the sky over Squamish at the height of the fire, and residents to the south of the building were asked to evacuate briefly because of air quality concerns.

David Lu, owner of the nearby Squamish Athletic Club, said the smoke was blowing away from his business and towards Vancouver.

"We were OK," he said. "It was a big, big fire ... with blue, yellow, white and grey smoke."

Just before noon, Squamish RCMP said evacuated residents could return but cautioned that they should keep windows and doors closed and limit outdoor activity until the fire is out.

Stoner said the burned building looks to be a total loss.

Roads around the area remain blocked off as crews work to put out what remains of the fire.

Big fire in downtown Squamish. It's at main street and is a warehouse. First responders are on the scene. Looks nasty. <a href="https://twitter.com/hashtag/downtownSquamish?src=hash&ref_src=twsrc%5Etfw">#downtownSquamish</a>. <a href="https://twitter.com/hashtag/Squamish?src=hash&ref_src=twsrc%5Etfw">#Squamish</a> <a href="https://twitter.com/hashtag/Squamishfire?src=hash&ref_src=twsrc%5Etfw">#Squamishfire</a> <a href="https://t.co/KlfgmXGnkb">pic.twitter.com/KlfgmXGnkb</a> —@Cherylmacn

The District of Squamish said it was consulting Vancouver Coastal Health environmental health officers about air quality and would issue an advisory if necessary.