A campus supervisor had to use a bullhorn Monday to let students know when each period was done because the bell system wasn't working.
Saturday's fire damaged the administration building.
Offices were burned, along with trophies and medals.
Everything inside the building was a total loss. Damage is estimated at $250,000.
The fire was ruled an arson. The cause of the fire was under investigation.
Anyone with information is urged to call the San Bernardino County Fire Department at (909) 387-5974