The fire was reported around 5:35 a.m. at Junipero Serra High School on Van Ness Avenue. The flames were quickly extinguished.
AIR7 was over the scene where a section of bleachers and a possible press box were engulfed in flames. Firefighters were trying to stop the fire from spreading into what was believed to be the locker rooms just behind.
The cause of the fire was not known.