The fire started just before 5 a.m. at the business on Brawley Avenue near Nielsen Avenue.
Firefighters say a man living in the building lit a lantern before going to sleep and a short time later he woke up to flames. They say the building did not have any power and was being used for storage.
The man says he had permission from the owner to live in the building. The fire was quickly put out and no one was injured.