The power was out Wednesday at for just under an hour during instruction time.
Allison Zaragoza, a spokeswoman for San Diego Gas & Electric, said a fuse serving only the school failed at 9:27 a.m. Power was restored at 10:23 a.m.
Principal Curt Visca said the primary areas affected by the outage included the school office and classrooms in the main building.
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"I walked around to every class first thing in the morning when school started, and it was 'business as usual,' except for a few darker classes," Visca said. The classrooms do have some natural sunlight.
Fortunately, no students were in the middle of a computer lab or other electricity-intensive activity, Visca said.
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"Some classes took students outside for a short time for PE when SDG&E turned off all electricity in the main building," Visca said.