A woman opened fire with a handgun at the campus headquarters of the Youtube social media website near San Francisco Tuesday, wounding three before killing herself.
Police have not yet identified any of the victims or the shooter, but say they believe it was part of a domestic dispute.
A hospital spokesman in San Francisco says it is treating the wounded -- two women in fair condition and a man who was in critical condition as of late Tuesday.
San Bruno, California Police Chief Ed Barberini says officers rushed to the Youtube campus after receiving numerous 9-1-1 calls. He says the shooter is believed to have opened fire at an outdoor patio, where employees were enjoying lunch.
Workers inside the building tweeted that they heard gunshots and people running as they huddled in the offices for safety. One man said he saw drops of blood on the floor and in a stairway.
The shooter's body was found in the building. One of the wounded women managed to escape to a nearby fast food restaurant.