LOS ANGELES—Twelve people are hurt, three critically, after flames swept through an old Los Angeles harbor area apartment building.

City News Service says the injured include a badly burned resident, a resident who jumped from a second-floor window and a police officer treated for smoke inhalation.

City fire spokesman Erik Scott says the blaze broke out after 3 a.m. Tuesday on the second-floor of the two-story, 14-unit San Pedro apartment building.

It took 150 firefighters 34 minutes to extinguish the blaze. The building was constructed in 1923.

Scott says firefighters returning from a medical call spotted the fire before a 911 emergency call was received.

Investigators are trying to determine the cause of the blaze.