Residents rescued from burning apartment building in Albany Park

CHICAGO --  Firefighters rescued several people after flames raced through an apartment building on the city's Northwest Side.

The fire happened around 1 a.m. Thursday at a building in the 3800 block of W. Montrose. The fire broke out in the rear section of the apartment building.

Firefighters made a number of rescues by ladder from the upper floor of the three-story building.

Four people -- including a young boy -- were injured, and transported to Swedish Covenant Hospital.

Among the injured is a 12-year-old boy and his 39-year-old mother -- and from another unit, a 48-year-old woman and 30-year-old man.

Fire officials say all were suffering from minor smoke inhalation and should recover.

More than a dozen people are displaced by the fire. They are receiving assistance from human services and the Red Cross.

The cause of the fire is unknown and is under investigation.

Some residents believe the fire was purposely set by a problematic tenant.