Firefighters spent hours Wednesday battling a fire that destroyed a historic building in downtown Montreal.

The five-alarm fire broke out in the morning on Park Ave. just south of Milton St.

Witnesses began reporting huge plumes of black smoke at the R.S. Muir & CO. building at 9 a.m. Built in 1875, the vacant, barricaded building was regularly occupied by squatters.

Montreal police confirmed the building was broken into as recently as two days ago, while the fire chief said there were plenty of combustible materials inside.

By midday it was obvious the building could not be saved, and with flames spreading to Alto Restaurant next door, the only way to gain control was to tear down the building.

Eyewitness Angie Biron noticed smoke in the air around 8:30 a.m. Wednesday.

“It started out not that big, but maybe an hour or so later, the smoke was huge,” Biron told CTV News Channel. “The sky was just grey.”

Biron said firetrucks began to arrive and emergency responders “started asking people to get out of the street.”

Witness Momo El Salahi tweeted that parts of the roof collapsed under the intensity of the flames.

Like the fire that broke out last week in Chinatown, this building was on the fire department's watch list of dangerous buildings.

Vacant, with open floors, crews examined the building every six months.

"The station has to visit it twice a year to make sure it didn't change, so we know exactly what we're facing," said Fire Chief Pierre Limoges.

Mayor Denis Coderre said the Plateau-Mont-Royal borough building was last inspected on July 4 and everything was considered safe.

The cause of Wednesday's fire is not known, but they suspect it was started -- whether accidentally or deliberately -- by squatters.

Coderre said there will be an investigation.


Three families had to evacuate their homes on Wednesday and they will be cared for by the Red Cross.

No injuries were reported.

Meanwhile Projet Montreal is calling on the city to come up with a better plan to deal with abandoned buildings.

Anne-Marie Sigouin called for a registry of vacant buildings, and rules to make owners accountable.

She said similar things are done in Chicago.

"The fines are quite hefty, much more than they are here, so maybe we can look at other cities and what they do," said Sigouin

Coderre said Montreal is building a registry in conjunction with Heritage Montreal.