A fire at an apartment in Hawaii Kai caused moderate damage, according to fire officials.

Honolulu fire crews responded to the home on Kaumakani Street at around 1 a.m. Friday.

The fire was in a studio apartment attached to a house.

Flames were confined to a bedroom and it was quickly controlled.

Fire officials said the blaze was caused by unattended smoking material that ignited the bedroom mattress.

Damage is estimated at $15,000.

One person lived in the studio apartment but was not home when the fire occurred.