The Fairbanks Fire Department responded the fire in the 200 block of Craig Street about 3:45 a.m. The home was full of smoke when firefighters arrived, but as they entered a small explosion occurred and fire rolled across the ceiling, causing burning tiles to fall on firefighters, according to a press release.

The fire was quickly brought under control, but firefighters spent several hours shoveling out smoldering insulation from the ceiling.

The blaze started near an older oil-fired forced-air furnace, and firefighters believe a malfunction in the furnace may have been responsible for the fire.

The owners, a man and woman, were asleep on the first floor of the building at the time of the fire while another couple was sleeping in the apartment on the second floor. All four individuals and their pets were able to escape the home uninjured.

Damage to the house, which firefighters say is no longer habitable, is estimated at $175,000. The house was insured. Residents are staying with friends and family.