A passerby reported seeing smoke and flames shooting from the roof of the unoccupied IBM plant on Concord Drive between Hayes Avenue and Cottle Road at about 1:30 a.m., San Jose fire Capt. Anthony Pianto said.
The fire is not yet controlled but is not expected to spread beyond the building where the flames ignited.
Firefighters surrounded the building but the flames reportedly refuse to subside, according to Pianto.
"We have heavy, active flames and smoke," Pianto said at about 4 a.m.
The burning building reportedly has multiple wings and at least one portion of the structure collapsed in the flames, according to Pianto. "We're in the middle of this fight," Pianto said. "The fire is still burning pretty good."
The building was built in 1957, according to IBM representatives. No injuries have been reported and the cause of the fire remains under investigation, Pianto said.
