A veteran firefighter is in an intensive care unit with critical injuries after falling from a roof while battling a fire in a vacant building in Toronto’s downtown, early Saturday.

“Overnight, two of our firefighters were injured battling a fire. One firefighter remains in serious condition. We are all praying for the recovery of both firefighters and @Toronto_Fire is doing everything it can to support their families at this difficult time,” Mayor John Tory tweeted.

Tory told CP24 that the firefighter who sustained serious injuries is Jim Warren, a captain and 36-year veteran of the fire service.

Warren is said to be in critical condition at St. Michael’s hospital. The other firefighter broke his leg but is in stable condition.

Toronto fire chief Matthew Pegg said the men were working on the roof to ventilate the building and enable crews to go inside and called it “dangerous work.”

“It’s dark, there’s a large volume of smoke,” said Toronto fire chief Matthew Pegg, describing the environment that the firefighters were working in to reporters at the scene on Saturday afternoon.

Fire crews were called to the scene around 2 a.m. Saturday for the three-alarm fire in near the intersection of Shuter and Jarvis Sts.

Toronto fire district chief, Stephan Powell said the firefighters fell off the roof as a result of “extremely bad” smoke conditions and that it’s possible the firefighters thought they had safe footing because the roof had several levels. Paramedics rushed them to hospital, shortly afterwards.

Pegg tweeted his thanks to the first responders treating the injured firefighters.

“It’s something all of us feel. There’s a real sense of concern almost from a family level,” said Pegg.

Loading... Loading... Loading... Loading... Loading... Loading...

Firefighters have a peer support and chaplain program to ensure that they can cope and have the appropriate resources to deal with incidents like this, he said.

Pegg said the operation was particularly difficult because the building was abandoned and it was unclear whether anyone was inside.

“Our first goal always is, and will always be, the rescue of people that may be trapped,” Pegg said. “Dealing with and responding to fires... especially when we cannot confirm if everyone is accounted for and safe, means that our people will assume and take on a considerable amount of risk.”

Toronto Fire says the fire is now out at the building and the cause is under investigation.