A suspected female shooter is dead and three others are injured after a mass shooting at YouTube’s headquarters in San Bruno, Calif., Tuesday afternoon, according to San Bruno police.
Police are still investigating the scene, but confirmed the suspected shooter was found dead with what appears to be a self-inflicted gunshot wound inside the building, San Bruno Police Chief Ed Barberini said at a press conference Tuesday afternoon.
All 1,100 employees who worked at the YouTube headquarters evacuated the building, which is about 10 miles from downtown San Francisco in the heart of Silicon Valley.
President Donald Trump has been briefed on the YouTube shooting. “Our thoughts and prayers are with everybody involved,” he wrote in a tweet just before 6:00 p.m. E.T. “Thank you to our phenomenal Law Enforcement Officers and First Responders that are currently on the scene.”
Here’s what we know about the shooting at YouTube’s San Bruno headquarters:
What do we know about the YouTube shooting?
YouTube employees began tweeted there was an active shooter and heard noises that sounded like gunshots just before 1 p.m. PT.
Vadim Lavrusik, a product manager at YouTube headquarters according to his verified Twitter account, tweeted that he “heard shots and saw people running while at my desk.” Lavrusik added that he was “barricaded inside a room with coworkers” before later tweeting that he was evacuated and safe.
Todd Sherman, another product manager at YouTube HQ according to his Twitter, quoted Lavrusik’s tweet, writing, “We were sitting in a meeting and then we heard people running because it was rumbling the floor. First thought was earthquake.”
“We headed towards the exit and then saw more people and someone said that there was a person with a gun,” Sherman added in another tweet, before writing, “I looked down and saw blood drips on the floor and stairs. Peaked around for threats and then we headed downstairs and out the front.”
One Twitter user posted an image of what appears to be people outside of the YouTube building with their hands up.
Google, the parent company of YouTube, addressed the incident in a statement on its communications account. “Re: YouTube situation, we are coordinating with authorities and will provide official information here from Google and YouTube as it becomes available,” Google said. Google did not immediately respond to a request for comment from TIME.
How many victims were there in the YouTube shooting?
Who was the shooter?
San Bruno Police Chief Barberini said investigators found one deceased woman at the scene with what appears to be a self-inflicted gunshot wound, but he could not confirm that for certain, nor could he confirm if she was the assailant.
Investigators believe she is the shooter.
How many people work at YouTube’s San Bruno headquarters?
More than 1,100 employees — including engineers, sales teams, analysts and more — work at YouTube’s San Bruno office, which is located 12 miles south of San Francisco and about 26 miles north of Google’s headquarters in Mountain View. The multi-level facility, which was reportedly bought by Google in 2015, includes a basketball court, a lap pool and a slide connecting the second and third floors.
This story is developing and will be updated.