Three people are out of their homes in northwest Calgary after a fire broke out in one of the units of fourplex on Monday evening.

Crews were called to respond to reports of a fire in the 8900 block of 34 Avenue N.W. and, upon arrival, they found three adults outside a fourplex.

The group said that one of the lower level units was on fire at which point crews entered and quickly extinguished the blaze.

Firefighters conducted a search and determined that no one else was inside and no one was at home at the time of the fire. Two other people were in the adjacent units in the building which needed to be evacuated as a precaution.

Crews say that the fire was initially reported by one of the men in the affected unit who heard the fire.

Investigators discovered that the suite was equipped with smoke detectors, but the battery was dead so it did not go off.

Fire crews remind residents to inspect their smoke detectors and change batteries twice a year.

Detectors should also be replaced every ten years.

The cause of the fire is under investigation and the Red Cross is helping the affected residents.