A female shooter stormed YouTube's headquarters in San Bruno, California, injuring four people before turning the gun on herself.
The "white adult female" was found dead from a self-inflicted gunshot by police inside the building. Four other people were injured, including a man, 37, who was taken to hospital with critical injuries.
Two women were also injured in the shooting. One is listed as "serious" and the other is "fair". Another person is believed to have non-life threatening injuries. Two victims were found at a nearby business, said San Bruno police chief Ed Barberini.
A worker at a Carl's Jr restaurant next to the YouTube campus said one woman was shot in the carpark and brought into the restaurant to be cleaned up.
Witnesses told Fox News the woman shot her boyfriend and then herself, but police have yet to confirm that.
A spokesperson for Zuckerberg San Francisco General Hospital said at least five patients have arrived from the shooting and more are expected. Stanford Hospital said up to five patients were on the way to hospital. Their conditions and injuries are unknown.
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Staff told media outside the building that a female employee was shot in the left leg. Another staff member used a bungee cord as a tourniquet to slow the bleeding.
https://twitter.com/SkyNews/status/981277589837791232Another witness said the shooter showed "no mercy" as a female was shot multiple times.
https://twitter.com/NBCNews/status/981278771381768193
Vadim Lavrusik, who works on YouTube's product team, tweeted that he heard shots and saw people running.
"Now barricaded inside a room with co-workers," he wrote. He later tweeted that he had safely left the building.
Todd Sherman, a product manager at the company, described the frightful moments evacuating the building.
"I looked down and saw blood drips on the floor and stairs," he wrote on Twitter.
"Peaked [sic] around for threats and then we headed downstairs and out the front."
Videos shared on social media appeared to show workers leaving the building, their hands above their heads, and police rushing in.
People near the area reported hearing shots fired and seeing police activity and lockdown procedures.
About 1700 people work at the 157sq m YouTube campus.
Michelle Tam, a hostess at the Hashes & Brews restaurant about a block away from the company's headquarters told the Los Angeles Times three YouTube employees came into the restaurant, visibly shaken.
"They came in from a back door," she told the newspaper. "They sat down at a table. They were in a daze. One guy, there was a little blood on his head."
One had a partial fragment of a bullet in her shoe, Tam told the Los Angeles Times.
Salahoden Abdul-Kafi, a YouTube product manager said the shooter "had a shooting mask on, full body armour and was calmly walking and firing a handgun".
"We jumped to the floor then ran as fast as we could."
Google, which owns YouTube, said it was cooperating with authorities.
"We are coordinating with authorities and will provide official information here from Google and YouTube as it becomes available," the company said.
The White House says President Donald Trump has been briefed on the YouTube shooting. He has since tweeted:
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