Station was activated @ 03:30 for a first alarm assignment for a appliance fire fire district 42 (Jackson Twp.).  Engine 17-2 (with 4) responded and arrived to assist crews from 42 and 43 with ventilation.  Crews from 42 arrived to find a small fire in the basement due to extension cord malfunction, fire had burned into the floor joists containing a water line.  Which had melted and helped to extinguish the fire.  Interior crews extinguished fire and began ventilation, with further investigation their was slight extension to the first floor bathroom.  Crews remained on scene for approximately 2 hours.  Smoke detectors helped the family find the fire and escape safely.