THOUSAND OAKS (CBS) — Ventura County fire investigators are combing through the rubble of an apartment fire that killed a woman and displaced 12 people early Thursday.

The fire was reported just before 3 a.m. at an apartment near West Olsen Road and Mountclef Boulevard, by Cal Lutheran University, and was knocked down within 30 minutes.

The body of a woman was found on the third floor of the complex where the fire was raging, according to the Ventura County Star. She appeared to be the only person living in the unit.

The Ventura County Fire Department received several calls about the fire. When firefighters arrived, they saw flames coming out of the burning unit’s door, fire spokesman Capt. Ron Oatman told the Star. Firefighters found the woman dead in the apartment as they fought the flames and searched the building.

There were no other injuries. The American Red Cross was on scene to assist the displaced residents with housing.

An estimate of damages and the cause of the fire was not available.