MONTREAL -- No one was injured but six people needed to be evacuated after a residential building caught fire on Gerald Ave. in LaSalle Tuesday.

According to Karine Huard of the Montreal fire department (SIM), a fire broke out on the back balcony of a second-floor apartment around 3:20 p.m. near Champlain Blvd. and spread to the roof.

Four residences required evacuation, and there is heavy damage to the second floor and roof. The residents have been relocated.

The cause of the fire is unknown and firefighters remain on the scene.

The smoke detector in at least one apartment was functioning, and the fire department is reminding citizens to check and ensure smoke detectors are functioning.