A fire investigator was searching for the cause of a fire Tuesday night that damaged at least one apartment unit and forced dozens to evacuate an apartment building in Moiliili.

The fire started at about 7:34 p.m. in a sixth-floor unit at Scenic Tower, 796 Isenberg St., said Honolulu Fire Department Capt. Kevin Mokulehua. He said the 19-story building was more than 40 years old and did not have a sprinkler system. The building’s fire alarm system, however, was working and residents began evacuating before firefighters arrived.

Fire at a Scenic Tower 796 Isenberg Street. pic.twitter.com/TfyaYf1O6m

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About 35 firefighters responded and found heavy smoke and flames coming from the sixth-floor unit. Firefighters brought the fire under control at 7:50 p.m. and extinguished it at 8:51 p.m.

Mokulehua said one man, who lived alone in the unit, was not home when the fire started.

At about 8 p.m., residents were allowed to return to their units, except for those on the sixth floor because of smoke and the ongoing fire operations.

The American Red Cross was assisting. No one was injured.

Damage from the fire was estimated at $130,000.