The owner of a business next to a Winnipeg heritage building severely damaged by fire over the weekend said a blaze was inevitable because squatters routinely break into the vacant structure.

Firefighters spent 10 hours early Sunday dousing a fire at the 110-year-old Keewayden Block, a seven-storey structure also known as the Jacob-Crowley Building, which sits less than a block east of Portage and Main, near the Fairmont Hotel and Shaw Park.

The fire engulfed the building's roof, partly collapsed its elevator shaft and moved into the block's basement, the Winnipeg Fire Paramedic Service said. The cause of the fire has yet to be determined.

Leslie Bester, who runs an internet, phone and data-centre company in a building next to the damaged block, said he's witnessed people who are not construction workers climbing up the scaffolding at the rear of the building, hanging around inside it, exiting the structure and attempting to strip parts from a truck abandoned its parking lot.

Bester said police and fire officials have been made aware of the squatters entering and exiting the building, which was in the process of being converted into a Hyatt Place hotel.

"There hasn't been any activity here for quite a while," said Bester, pointing to a first-storey window he boarded up himself to reduce the threat of people entering the building and potentially causing a fire.

"Frankly, I predicted it. I mean, the weather is getting cold. People are going to start going inside for warmth. It's a downtown, abandoned building and it's not like a super-high-traffic area at Portage and Westbrook here," Bester said.

"I would have been surprised if it didn't burn by spring. I was expecting it."

Les Bester, who took it upon himself to board up a window in the vacant Keewayden Block said he feared a fire would strike the building after seeing people climb its scaffolding 'every day.' (Tyson Koschik/CBC)

According to the city, the Keewayden Block is not abandoned. City property inspectors have visited the building four times since June 2018 to inspect progress on two separate work permits, city spokesperson Kalen Qually said in a statement.

"As of the most recent inspection in April 2019, interior demolition remained in progress," Qually said.

The block was undergoing a conversion into a hotel.

Bester said he has not seen any substantive work take place at the block since late 2018. He said complaints led workers to attempt to restrict access to the scaffolding and ladders at the rear of the building, but the barriers are easily bypassed.

"There's people climbing these buildings every day actually. Like, literally every day," said Bester, who has placed a series of security cameras on his building.

Hours before the fire began, one of those cameras captured an image of someone ascending the building, he said.

Bester said anyone who wants to access the scaffolding at the rear of the Keewayden Block need only to slip between these plywood boards. (Tyson Koschik/CBC)

The block, completed in 1909, was added to the City of Winnipeg's list of heritage resources in 2017.

At the time, a company called No. 16 Hospitality Ltd. was converting the building into a Hyatt Place hotel. In a mortgage offering that promised investors a return of 10 per cent, per year, it sought $5 million in funding for a project described as a $27-million buildout.

According to city tax records, the property is assessed at $3.1 million. Land titles list the owner as Zhabba Inc., which in turn lists Richmond Hill, Ont. achitect Harry Christakis as its director, according to corporate records.

The mortgage offering for the project lists Christakis as one of the principals in the No. 16 Hospitality project. He could not be reached for comment via phone or email.

There are several construction liens against the building, as a well as a notice exercising power of sale, dated January 2019, but the title continues to belong to Zhabba Inc., according to records.

Heritage Winnipeg executive director Cindy Tugwell said she was unaware the project had slowed. The fire took her by surprise, she said.

"That's why we hate vacant buildings. They're sitting ducks for this kind of stuff," said Cindy Tugwell, executive director of Heritage Winnipeg.

The Winnipeg Fire Paramedic Service was slated to return on the hour Sunday evening "to ensure hot spots remain extinguished and there's no remaining risk at the site," Qually said.

Jason Shaw from the Winnipeg Fire Paramedic Service describes the scene:

Firefighters were called to the building under renovation at 138 Portage Avenue East just after 2:30 a.m. where they found heavy flames pouring out of the roof. 1:13

Bester said he believes the city could have been more proactive in preventing the blaze.

"What was it, like 13 fire trucks here for 12 hours?" he asked. "[Look at] the cost of what just happened versus the city coming up with four-by-eight sheets of plywood and just boarding it up."