The Honolulu Fire Department has determined that the cause of a house fire in Laie on Sunday was incendiary, meaning “intentionally ignited in an area or under circumstances where and when there should not be a fire.”

HFD officials said the fire at 55-20 Kamehameha Highway originated in the crawl space under the house, which was being used as living quarters.

Honolulu firefighters responded to a 3:45 a.m. call Sunday for a two-alarm blaze, initially reported at 55-017 Kamehameha Highway, the address for Kokololio Beach Park just north of Hauula.

Upon arrival six minutes later, firefighters found a vacant, single-story residential home engulfed in flames.

No occupants were found inside at the time, according to HFD. The fire was fully extinguished at 4:45 a.m.

Damages are estimated at $632,000 to the home and $10,000 to contents, HFD said. An adjacent home at 55-22 Kamehameha Highway suffered $12,000 in damages to the exterior.