The fire, burning at an abandoned warehouse at 1880 Dobbin Drive, was reported at about 2:50 p.m. and contained by 4:40 p.m.
Kouns said firefighters managed to get into the 40,000-square-foot building and are working to extinguish the fire. The heavy black smoke surrounding the warehouse is dissipating, he said.
There have been no reports of injuries.
Santa Clara County firefighters responded to assist.