The Winnipeg Police Service arson unit continues to investigate a fire that destroyed a business on St. Mary's Road on Sunday.

Fire crews responded to the fire in the 400 block of St. Mary’s Road near Guay Avenue shortly after 11 a.m. on Sunday.

Heavy smoke billowed out over St. Mary’s Road from a large fire at a business Sunday morning. Police diverted on surrounding streets and evacuated nearby residences while firefighters battled the blaze.

On Monday, crews began demolishing the building, as it was declared dangerous. Damage from the fire is estimate at $1 million.

"When the crews first arrived, they found heavily charged smoke," said Acting Platoon Chief Morris Semkowski. "They tried to make entry and they decided that wasn't safe to do, and made it a defensive fire."

Flames could be seen shooting through the roof and out of windows.

"By the time we pulled up here, everything was well-engulfed, heavy smoke, black smoke, that strange yellowy smoke, and just watched them set up the command," said Richard Brady, who witnessed the fire.

"They broke all the windows to try and ventilate it. Then there was flames leaping out of the window, and then coming out of the front windows. Usually you see lots of fire trucks up and down here, but I haven't see a fire along here in a really really long time."

There have been no reports of any injuries. No word yet on what caused the fire.