The Honolulu Fire Department said it continues to investigate the origin and cause of a two-alarm house fire in Hauula overnight.

Ten units staffed with 43 personnel responded to the 3:45 a.m. call at at 55-017 Kamehameha Highway, HFD said.

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

After securing a water source and initiating an aggresive attack, the fire was reported under control at 4:08 a.m., at which time firefighters were able to determine via a visual search that no occupants were inside.

HFD said the fire was fully extinguished at 4:45 a.m. A damage estimate was not immediately available as of this morning.