UPDATE | Woman believed to be YouTube shooter is dead

Details are still a bit sketchy, but police in Northern California say a woman believed to be the shooter at YouTube headquarters is dead of a self-inflicted gunshot and four others have been wounded.

San Bruno Police Chief Ed Barberini told reporters Tuesday that the victims have gunshot wounds and were taken to hospitals.

A spokesman for San Francisco General Hospital says it received three patients. Spokesman Brent Andrew says a 36-year-old man is in critical condition, a 32-year-old woman is in serious condition and a 27-year-old woman is in fair condition.

He says the hospital is expecting more patients but doesn't know their conditions.

 A city official says there were multiple 9-1-1 calls reporting a shooting earlier this afternoon. 

T-V helicopter video shows officers patting down people grouped outside a building and police vehicles surrounding the area.
Calls and emails to YouTube representatives were not immediately returned