UPDATED: A woman who opened fire at YouTube’s San Bruno, Calif., headquarters on Tuesday afternoon has been identified by police as Nasim Aghdam.

Aghdam was a YouTube user and posted numerous videos to the site under the name Nasime Sabz. In one January 2017 video, she says that the company engaged in discriminatory and unfair filtering practices, and that her videos used to get many views before she was filtered out. She also complains about a workout video getting age-restricted, resulting in fewer views, and, in another video, her channel being demonetized after YouTube’s new February ad policy.

Law enforcement earlier confirmed at a press conference that that shooter is dead, apparently of a self-inflicted gunshot wound. At least four victims sustained injuries and were transferred to the Zuckerberg San Francisco General Hospital, but no additional fatalities have been reported yet.

According to CNN, of the victims, one 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.

Authorities first confirmed an active shooter situation at about 1:30 p.m. PT on Tuesday, urging visitors to stay away from the area.

We are responding to an active shooter. Please stay away from Cherry Ave & Bay Hill Drive. — San Bruno Police (@SanBrunoPolice) April 3, 2018

At about 1 p.m. PT on Tuesday, Vadim Lavrusik, whose Twitter bio says he works in product at the company, tweeted, “Active shooter at YouTube HQ. Heard shots and saw people running while at my desk. Now barricaded inside a room with coworkers.”

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

Google CEO Sundar Pichai released a memo on Tuesday afternoon saying that the situation was contained.

“It’s with great sadness that I tell you — based on the latest information — four people were injured in this horrific act of violence,” Pichai said. “We’re doing everything we can to support them and their families at this time.”

Here is the note that @sundarpichai just sent to Googlers worldwide. pic.twitter.com/bdC6KeTl9c — Google Communications (@Google_Comms) April 3, 2018

More social media reports emerged from YouTube’s headquarters throughout the day. Todd Sherman, a product manager at YouTube, tweeted that he was in a meeting when he began to see people running.

“We headed towards the exit and then saw more people and someone said that there was a person with a gun. S—,” he wrote. “At that point every new person I saw was a potential shooter. Someone else said that the person shot out the back doors and then shot themselves.”

“I looked down and saw blood drips on the floor and stairs,” he added. “Peaked around for threats and then we headed downstairs and out the front.”

After existing the room we still didn’t know what was going on but more people were running. Seemed serious and not like a drill. — Todd Sherman (@tdd) April 3, 2018

At that point every new person I saw was a potential shooter. Someone else said that the person shot out the back doors and then shot themselves. — Todd Sherman (@tdd) April 3, 2018

YouTube’s San Bruno offices host more than 1,700 employees across multiple buildings. The offices are located south of San Francisco, adjacent to a major freeway and close to the San Francisco International Airport.

The shooting is said to have taken place in the main office — a 200,000-square-foot building that is fairly accessible from the outside, with a big open lobby that dons an oversized version of the famous YouTube logo as well as a video wall playing some of the service’s most popular footage on an endless loop.

There is no word yet on how the suspected shooter was able to enter the building, which sees regular visits from YouTubers and their fans. Visitors are asked to check in at the front desk, and doors are restricted to employees with badges. Large sections of YouTube’s office space have an open floor plan. Overall, across multiple buildings in San Bruno, Google and YouTube lease more than 1 million square feet of offices.