SOUTH SAN FRANCISCO (CBS SF) — A three-alarm fire at a South San Francisco apartment building appeared to be contained after firefighters battled the blaze for an hour.

The fire was reported at 4:55 p.m. at 610 Olive Ave. Two alarms were called initially before the fire escalated to three alarms.

Live video from Chopper 5 showed firefighters at the scene mopping up. Heavy damage on the second and third floors was visible. Burn marks can be seen around several of the windows.

Crews from at least two fire stations responded.

When firefighters first arrived, they could see flames actually shooting out of some of the windows.

The initial location of the fire and what may have caused it have not been determined.