Police did not give a motive for the shooting, although U.S. media reported that the suspected shooter may have been attempting to shoot her boyfriend.
Aghdam, who was 39 years old, is believed to have carried out the attack because of a domestic dispute, officials said.
"We were sitting in a meeting and then we heard people running because it was rumbling the floor". She and others hid in a conference room for an hour while someone called 911 repeatedly for updates.
Rep. Jackie Speier (D-Calif.), whose district includes the YouTube headquarters, said she was "shocked and saddened to hear about another mass shooting".
"Our thoughts and prayers are with everybody involved", Trump tweeted. "Thank you to our phenomenal Law Enforcement Officers and First Responders that are now on the scene", he said. I am also an editor for Turning Point News and a foreign correspondent for Snip.And in case you were wondering, it's supposed to be pronounced "Wit-2". He would not say if anyone was dead. Authorities did not release names of the victims. "Several minutes later, while conducting a search of the premises, officers encountered a second individual with a gunshot wound that may have been self-inflicted". Two of the shooting victims were discovered at "an adjacent business", police said.
A shooter opened fire at YouTube's United States headquarters in San Bruno, near San Francisco, on Tuesday.
A spokesman for San Francisco General Hospital said the hospital is receiving patients but did not say how many. A 32-year-old woman is in serious condition, while a 27-year-old woman is in fair condition. Their conditions are unknown.
Barberini said "we don't know the circumstances" of why the woman opened fire, adding the investigation is just beginning.
Stanford Health Care said they are expecting 4-5 patients from the shooting, CBS News correspondent Jamie Yuccas reports.
Lavrov says spy poisoning could be 'in interests' of UK govt
He also, however, defended the decision to expel diplomats, "to show solidarity with Britain but also as a signal of unity". Writing in The Sunday Telegraph, UK Defence Secretary Gavin Williamson said the world has entered "a new era of warfare".
Employees were seen in several videos posted to social media being walked from the building with their hands above their heads.
YouTube is owned by Google whose main headquarters are based in northern California.
Bryson Masse, a reporter who doesn't work for YouTube but was in the area, posted videos from outside the building that show police and emergency professional responding to the situation.
"My stomach sinks with yet another active shooter alert".
The San Bruno Police tweeted at 1pm local time advising people to avoid the area, reports KRON4. There was no other immediate information.
One man said, "Active shooter at YouTube HQ". Sky Fox showed people walking out of the building being patted down by police.
San Bruno police said they could not provide more information about the incident.
Calls and emails to YouTube representatives seeking comment were not immediately returned.
There are multiple reports of an active shooter at YouTube's headquarters in San Bruno.
Further details are unavailable at this time.