Crews started fighting the fire at the rear of the building where they found the blaze raging in a garage.
The fire then spread up from the garage into the storefront buildings and residences above.
At least 100 firefighters battled the blaze
“We’ve had several firefighters up on the roof trying to figure out where it spreads,” said Division Commander Bob O’Hallarn at the scene early Thursday morning.
O’Hallarn says two firefighters sustained minor injuries trying to put out the fire and were taken to hospital for treatment.
As of 5:30 a.m., fire crews had knocked down the fire, but were still monitoring it for hot spots.
“We knock it down and then it flares up in another spot because it travels through those void spaces,” said O’Hallarn, referring to an attic space shared by some of the addresses on that stretch of Dundas. The Ontario Fire Marshal will be notified because of the severity of damage caused to the buildings, according to O’Hallarn.
Dundas Street West has reopened, and regular streetcar service has resumed.