The Montreal fire department says a lit cigarette is to blame for a fire that destroyed a building Saturday morning.

More than 125 firefighters were called in around 3 a.m. to put out the flames at the Frontenac St. building. The fire took more than eight hours to extinguish.

A spokesperson for the fire department says someone was smoking behind the building and the still-lit cigarette slowly burned what was around it before the flames spread to the building, which houses a business on the first floor and residents on the second. That building is a total loss.

The fire also spread to a neighbouring building, which was evacuated.

Ten people are now homeless and the Red Cross is assisting them while they get back on their feet.