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A historic building in downtown Toronto will have to be "systematically dismantled" after sustaining massive structural damage in a major blaze early Monday, fire officials say.

Toronto firefighters were alerted around 4 a.m. to the blaze in a red-brick heritage building constructed in 1888 at 335 Yonge St.

Yonge and Gould Street, Toronto, ON

Thirty-two fire trucks and 125 firefighters were on the scene of the fire near Ryerson University, Toronto Fire Services Capt. Mike Strapko told CBC News.

The fire was eventually classified as a six-alarm blaze, which did not spread to neighbouring properties. Crews managed to get it under control by around 8 a.m., though they were still dousing the building as of noon.

"It was about as big as they get," CBC's Colin Butler said from the scene of the fire. "Flames were shooting high into the sky, and thick black smoke was obscuring buildings downtown."

The roof of the building and a structural wall both collapsed, Mike Ross, an investigator with the fire marshal's office, said at a noon news conference.

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"Unfortunately with the structural collapse we'll have to systematically dismantle the building," he told reporters. That process could take anywhere from a couple of days to a matter of weeks as the fire marshal's office tries to determine the cause of the blaze. During the time the building is being dismantled, the affected stretch of Yonge Street will be closed as a precautionary measure.

"It will all depend how the demolition of this building takes place ... and hopefully we can do it from at least the side of the building that, you know, doesn't cause any interruption," he said.

Yonge Street remains closed from Gerrard Street south to Dundas Street.

Dundas Street East is closed from Yonge Street to Victoria Street.

Ross couldn't say if investigators think arson was involved.

tp-yonge-fire

A busy stretch of Yonge Street could be closed for days as investigators probe the cause of a massive blaze that gutted a historic building near Gould Street.

"Can't confirm or eliminate anything at this point, but we'll take everything into consideration," Ross said.

"We can probably isolate the fire to the second or third floor right now. It's kind of hard to tell with the amount of stuff that has fallen down."

Key meeting just a week away

The three-storey heritage building, formerly the Empress Hotel, was constructed in 1888 and is the only surviving 19th-century building on the east side of Yonge between Gould and Dundas streets, according to a city staff report.

It was in the news last April when part of its front wall collapsed. That forced the closing of Salad King, an eatery in the building frequented by students from nearby Ryerson University.

The city was working on a plan to fully restore the building. But that is now not likely to happen, said Coun. Kristyn Wong-Tam, in whose ward the site is located.

Tam had arranged a meeting with city structural engineers on Jan. 10 to devise and implement a plan to restore the building.

"According to the fire chief, it would be very difficult to restore," she said. "It's pretty much gone."

The Ryerson campus will be closed for the day because of the fire.

'Horrific situation'

Three firefighters working at the blaze were taken to hospital as a precautionary measure, but they were not seriously injured.

"A couple of firefighters had somehow lost their footing and ended up falling from the neighbouring property into the fire building," Strapko told CBC News.

He said rapid intervention teams were deployed and got the firefighters out safely.

Speaking later Monday morning at a news conference at the scene, Toronto Chief Bill Stewart told reporters that the firefighters were rescued from the building within 25 to 30 minutes. 

"But as you can appreciate, it's a very horrific situation for the firefighters on scene to … locate them in the smoke, to find out where they are, and extricate them from the building," he said. "But the training that we put our people through worked, worked effectively, and you can tell by the smiles on the fellas' faces this morning. It was a good rescue."

Stewart couldn't say what caused the fire.

A fourth firefighter also required medical attention, but opted to stay and battle the blaze, Strapko said. No one else was hurt.

The fire also forced the TTC to stop service on the 505 Dundas streetcar route between Bay and Church streets during the early morning rush hour, although regular service had resumed by 8:30 a.m. The 97 Yonge Street bus, however, was still being diverted.

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