A fire has broken out at the Apple Campus in Cupertino. A building is burning at 2705 #6 Valley Green Dr.

The fire started at approximately 10:00 p.m. It is a three-alarm fire.

Update: The fire was contained at about 12:30 a.m. Santa Clara deputy chief, Hal Rooney said that the fire may have started in the air conditioning unit on the second floor. Employees in the building called in the fire.

An Apple representative is expected to give an official comment soon.

Source: CBS 5