Firefighters responded to reports of a fire at Independence High School at 1776 Educational Park Drive at about 12:35 p.m., San Jose fire Capt. Reggie Williams said.
The one-alarm fire was contained at about 1:15 p.m., Williams said. Smoke was still coming from the building at 1:30 p.m.
No had been injured by the blaze.
Investigators remained at the scene determining the extent of the damage to one building, he said.
Preliminary information indicated that the cause of the fire appeared to be suspicious.