Resident Luc Lalonde was inside the building when the fire broke out around 5:30 a.m. Wednesday.
He said the building was a rooming house where six people lived.
The two-storey structure was squeezed between two larger commercial buildings on St-Urbain Street between Jean-Talon Street and Mozart Avenue.
The fire took 30 firefighters an hour to put out. In the end, the building was completely destroyed.
"I have to go and call my father and tell my father I have no place to stay," Lalonde said. "I’m probably going to go to the Old Brewery Mission [homeless shelter]."