A family of six was left homeless Friday night after a fire destroyed most of their Plainfield home, Deputy Fire Chief Jon Stratton said.

Investigators were still on the scene early Saturday morning trying to determine the cause of the fire at 25030 W. Kay Drive, which started in the home's attached garage and worked its way into the walls and roof, Stratton said.

The fire was first spotted shortly after 9:30 p.m. by two young girls, ages 5 and 10, who observed smoke coming out of the electrical outlets and alerted their grandparents and mother, all of whom reside at the house, he said. The older couple's son was not at home at the time of the fire.

Although the fire started in the garage and destroyed a vehicle, it's not believed the blaze has any connection to the recent string of arson fires on Hazelwood Drive, Stratton said.

Damage is estimated at about $60,000.

No injuries were reported but the two girls were treated on the scene for minor smoke inhalation, he said.

Plainfield had about 48 firefighters on the scene, with assistance from the Oswego, Channahon, Troy and Minooka fire departments. It took about 15 minutes to get the fire under control.