Fire investigators are still trying to determine the origin of a two-alarm building fire that damaged a Waianae home Monday night.

One man was at home at 85-229 Ala Akau St. when firefighters responded at 8:14 p.m. Paramedics treated him for smoke inhalation, but he refused transportation to the hospital.

The first HFD unit arrived at 8:18 p.m. to find a one-story duplex with smoke and flames emanating from the rear of the structure.

The fire was brought under control at 9:10 p.m.