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Two families had to evacuated their Outremont homes after a fire broke out early Wednesday morning in a duplex.

One of the residents called 9-1-1 at 4:49 a.m., and when firefighters arrived on the scene six minutes later flames were burning at the rear of the building on Lajoie Ave. near Davaar Ave.

Eleven people escaped the building without any incident.

Firefighters tackled the flames and had it under control by 6:30 a.m.

The cause of the fire is not known, but firefighters have determined it started on the first floor at the rear of the building, then spread to the upper floor and the roof.

They say the damage to the building is extensive and the residents will not be able to returrn home until Thursday at the earliest.

(Source: CTV News)