A fire that left three people homeless in 'Ainakoa last night caused an estimated $500,000 damage, fire officials said today.

The fire gutted a single-story, wooden frame home at 4552 Ali'i Koa St. near Kahala Mall, causing $450,000 damage to the structure and $50,000 to its contents, said Fire Department spokesman Capt. Ed Kealoha.

A fire investigator determined that the fire started in a front bedroom, but could not pinpoint the cause of the fire, Kealoha said. However, investigators have ruled out an electrical problem as the cause, he said.

No one was at home at the time of the fire and no one was injured.