The cause of an early morning 3-alarm fire on Sainte-Catherine street remained unknown.
Officials said the blaze erupted inside a first floor pizzeria and spread quickly to the second and third floors.
It's believed squatters might have lived in the building since there was furniture on the upper floors.
More than a hundred firefighters fought the blaze for nearly two and a half hours before it was under control.
The apartment building next door was evacuated for a time.
There were no reports of injuries.