As crews arrived on the scene, they saw heavy fire coming from the roof.
Nobody was hurt, though one dog might have been lost.
Firefighters were also faced with intense heat as they battled the fire.
Officials say every one of the 15 units in the building was damaged.
A Deputy Chief told Eyewitness News the fire was caused by improperly discarded smoking material that landed on a deck and caught the deck on fire.
He adds that the Red Cross is helping 22 adults and two children who were displaced.
Two firefighters were taken to the hospital - one for a laceration, one a for heat-related condition.