More than 150 firefighters battled an apartment fire that began during the lunch hour in Cartierville.

Operations Chief Ian Ritchie said the fire started when someone on the third floor of 5450 Dudemaine St. left their stove unattended.

"They noticed that the fire started on the stove and very quickly went up into the range hood and spread throughout the apartment," said Ritchie.

From there, the fire spread to the fourth floor and the roof, but a firewall limited the flames to one section of the building. Firefighters took advantage of the firewall to chop a trench in the roof and ensure the flames did not cross the barrier.

With the fire in the roof, firefighters had to rip up the tar and gravel to make sure the embers had not gained a foothold.

"Also, because of the extreme cold, there are things that are freezing. The water is freezing, the firefighters are freezing. That's why we're in a fifth alarm, plus extra firefighters," said Ritchie.

The fire chief praised the STM and the Red Cross for providing buses to shelter the 100 people evacuated from the building. The Red Cross will also provide short-term shelter for the many people who will not be able to return home.