The Montreal fire department was called to a St-Henri apartment building on 740 Marin Ave. early Sunday morning at 1:30 a.m. after a neighbour called 911 about a fire that started near Atwater Avenue.
Fire department spokesperson Matthew Griffith said the fire spread to three other buildings — all residents were evacuated.
“Approximately six families have been evacuated and put into the care of the Red Cross,” said operations chief Ian Ritchie.
Up to 155 firefighters were rushed to the three-storey building to extinguish the flames.
Montreal police were called on site to help keep the situation under control.
The fire department was unable to identify the cause of the blaze — the arson unit is set to begin investigations later today.