Three people live in the house at 3950 Sierra Drive, but no one was home at the time of the blaze yesterday. Russell Kagesa, one of the residents of the home, said he did not know what started the fire.

Honolulu firefighters responded at 2 p.m. yesterday and found the house engulfed in flames, fire Capt. Kenison Tejada said. He said firefighters had the blaze under control by 2:20 and extinguished by 3.

Tejada said the home’s sloping lot complicated efforts to fight the fire on the second floor of the house.

"That fire was pretty hot," said neighbor Bill Lane.

Lane saw smoke start to come from the house’s first floor around 2. He said he ran around the house and yelled for the neighbors to call 911. Lane said he then tried to fight the fire but falling panes of glass hampered his efforts.

Tejada said the risk of structure collapse kept firefighters away from interior sections of the home, adding that hot spots in those areas probably rekindled the fire today.

Damage was estimated at $275,000 to the home and $35,000 to its contents; damage to one wall and a roof section of the neighbor’s home, 3954 Sierra Drive, was set at $10,000.