Onlookers and residents of the apartment building at 1635 Young St. gather on the sidewalk after evacuating their building in the early morning because of a fire in one of the units. Bruce Asato • The Honolulu Advertiser

Nobody was home in the second-floor apartment at 1635 Young St. when, just before 8 a.m., neighbors saw fire erupting from the living room and kitchen area of the two-level unit, said Capt. Richard Soo, fire department spokesman.

"They were 6-foot flames when I saw it," said Tony Catanzarite, who lives in an apartment facing the burning building. "The glass was already breaking out, and that's what woke me up."

The Red Cross has been summoned to provide emergency relief to the displaced family, a 45-year-old woman and her sons, 25 and 21, Soo said.

Damage was estimated at $150,000 to the building and $35,000 to its contents.