(CNN)The woman who shot three people at YouTube headquarters in Northern California has been identified as Nasim Aghdam, two law enforcement sources told CNN.
The woman took her own life after the shootings. She was found at the scene and appeared to have killed herself with a handgun, but the investigation is just beginning, San Bruno Police Chief Ed Barberini said.
“We know very, very little right now, and we probably won’t know more until tomorrow morning,” the chief said.
A fourth person was injured as people scrambled off the patio outside the cafe on campus.
The shooter is believed to have known at least one of the victims, two law enforcement officials told CNN.
The shooter’s motive was unclear, Barberini said, adding that it’s unclear whether the shooting was a domestic violence incident.
A spokesman for Zuckerberg San Francisco General Hospital, a level 1 trauma center, said the facility received three patients. One 36-year-old man was in critical condition, one 32-year-old woman was in serious condition and one 27-year-old woman was in fair condition.
Dr. Andre Campbell said the three patients were all conscious and none had yet gone into surgery. When asked how the patients reacted, Campbell said: “Shocked, like we are every time these terrible things happen.”
Man thought it was balloons popping
One witness inside a cafe near the shooting said the gunfire didn’t immediately register with him.
“It was a surprise, because you don’t really expect something like that,” the man told CNN affiliate KPIX. “I heard some pops, I obviously thought it was balloons, but then I thought that doesn’t make sense, not today. Then I heard more shots and that’s when everyone started scrambling for the door.”
Vadim Lavrusik, a YouTube product employee, tweeted he and others hid.
“Heard shots and saw people running while at my desk. Now barricaded inside a room with coworkers,” he wrote.
Active shooter at YouTube HQ. Heard shots and saw people running while at my desk. Now barricaded inside a room with coworkers.
— Vadim Lavrusik (@Lavrusik) April 3, 2018
Not long after the first tweet he wrote: “Safe. Got evacuated it. Outside now.”
Another YouTube employee said during the shooting people were trying to get out of the building “as fast as they could.”
She said she was on a conference call and a colleague, who heard shots, told her at least one person was shot on the patio where people eat.
“We were all suddenly aware of a lot of noises, of sounds, people running outside of the room where she was. And people screaming,” said the employee, who was in a building down the street.
” ‘I have to get out of here,’ ” the woman said her colleague said.
A witness told CNN he heard three or four shots and later more shots. He was in the drive-through line at a Carl’s Jr. fast-food restaurant across the street from an end of the YouTube building where there are tables with umbrellas on a patio.
A woman ran over to the Carl’s Jr. with a calf wound, he said. People at the fast-food restaurant tried to use napkins to stop the bleeding.