Update V: As details of the moments leading up to the shooting begin to emerge, NBC News reported that the still unnamed suspect was a woman in her 30s who opened fire on an outdoor dining area during lunchtime.

Authorities have also confirmed that they believe her motivation was a domestic dispute with a boyfriend.

* * *

Update IV: Police have confirmed that the shooter, who has not yet been named, did not work at YouTube but came to campus with the intention of shooting her boyfriend.

Police are now reporting that there were four victims, including the dead shooter. Reports have emerged that domestic violence could've been a motivating factor in the shooting. The boyfriend who was reportedly the target was probably the one male transported to San Francisco General. The hospital said of the three victims, he was in the worst shape. In addition, four or five patients were taken to Stanford hospital.

Zuckerberg San Francisco General Hospital spokesperson Brent Andrew says they have 3 patients:

• one male, 36, in critical condition

• one female, 32, in serious condition

• one female, 27, in fair conditionhttps://t.co/e0693S2kbv — NPR (@NPR) April 3, 2018

Witnesses said the shooting broke out at a party being held at the company headquarters, which is how she might've gained access to the building.

UPDATE:

San Bruno #YouTube HQ shooting:

- Female shooter committed suicide.

- 4 gunshot victims.

- Others are slightly injured due to running, stampede.

- Possibly domestic violence

- Conditions of the injured unknown. — BNL NEWS (@BreakingNLive) April 3, 2018

One witness shared his account of the incident with Fox.

#YouTube HQ shooting eyewitness: “I didn’t have a gun on me, but wish I did.” pic.twitter.com/GsBuNHatm0 — Josh Caplan (@joshdcaplan) April 3, 2018

* * *

Update III: President Trump has been briefed on today's shooting.

Was just briefed on the shooting at YouTube’s HQ in San Bruno, California. Our thoughts and prayers are with everybody involved. Thank you to our phenomenal Law Enforcement Officers and First Responders that are currently on the scene. — Donald J. Trump (@realDonaldTrump) April 3, 2018

* * *

Update II: San Bruno police in their first briefing since the shooting said they arrived at the scene at 12:48 pm PT two minutes after receiving a barrage of calls about gunshots at YouTube HQ, said San Bruno Police Chief Ed Barbarini.

Upon arrival, police encountered employees fleeing from the building and encountered one victim with a gunshot wound toward the entrance of the building. Later, while searching the premises, officers discovered a second victim with a gunshot wound that appeared to be self inflicted.

Two more victims were found at a nearby business.

Leaving a total of four victims that are receiving medical care, including the deceased suspect.

Police couldn't confirm that there was a second suspect - but did confirm the suspect was a woman.

The building has been evacuated and remains empty. The investigation is still ongoing.

* * *

Update: Bay Area politicians are already seizing the opportunity to advocate for stricter gun control laws.

Minority leader Nancy Pelosi, whose district is in San Francisco, said she and her staff are monitoring the situation.

My staff & I are closely following developments from the active shooter situation at YouTube HQ in San Bruno, CA. Thank you to our heroic first responders. Our Bay Area community – and all American communities – deserve real action to #EndGunViolence. — Nancy Pelosi (@NancyPelosi) April 3, 2018

Dianne Feinstein, a former mayor of San Francisco who was thrust into the national spotlight following the Moscone-Milk assassinations, said her stomach sank upon hearing the news.

My stomach sinks with yet another active shooter alert. I’m praying for the safety of everyone at YouTube headquarters. — Sen Dianne Feinstein (@SenFeinstein) April 3, 2018

Another YouTube employee said the shooter "had a mask on and full body armor" and was "calmly walking and firing a handgun.

Salahoden Abdul-Kafi, a #YouTube product manager said the shooter "had a shooting mask on, full body armor and was calmly walking and firing a handgun."



"We jumped to the floor then ran as fast as we could.”



Read more: https://t.co/s53HMubIgK pic.twitter.com/nZUr7kO9xQ — SFGate (@SFGate) April 3, 2018

KTVU reported citing witnesses who were "very close to the scene" that the female shooter killed herself after killing her boyfriend.

San Francisco General spokesperson confirmed three people taken there and five taken to Stanford. At SF General, two woman and one man were being treating for gunshot wounds, with the male victim in the worst condition.

* * *

Workers have reportedly been seen fleeing the YouTube headquarters in San Bruno, California, after shots were reportedly fired at the office.

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

The scene is no longer active. Law enforcement sources told ABC's Bay Area affiliate that the suspect was "a white adult female wearing a dark top and a head scarf." Authorities do not suspect terrorism, according to the Los Angeles Times.

Audio from the police dispatch played on KTVU said a female suspect is down and her gun recovered, but police are still looking for a male suspect - though earlier reports said there was only one shooter.

CNBC reported that the female shooter is said to be dead.

Confirmed: Active shooter at YouTube HQ in San Bruno. “It’s a very active scene,” police tell me. — Ryan Parker (@TheRyanParker) April 3, 2018

Around 1 pm PT, tweets bearing text messages claiming an active shooter had entered the building emerged.

My friend at @Google @YouTube in San Bruno says there's an active shooter on campus.



Really hoping this is somewhat of a hoax or blown out of proportion. 😕 pic.twitter.com/dkKbjHGEUj — Will Hudson (@MrWillToLive) April 3, 2018

The San Bruno city manager told Dow Jones that there is "no immediate threat" at YouTube HQ, located at 901 Cherry Ave. The San Matteo County PD appears to be the department in charge, according to KTVU.

The local ATF office is also responding, along with several other agencies. the California Department of Emergency Services has been asked to respond.

Police haven't provided much in the way of information, but footage from KTVU's news helicopter appeared to show a body covered with a tarp.

In a harrowing account posted to twitter, one employee said he saw blood on the floor and the stairs as he was fleeing the building.

We were sitting in a meeting and then we heard people running because it was rumbling the floor. First thought was earthquake. https://t.co/gmolQmRXm1 — Todd Sherman (@tdd) April 3, 2018

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

We headed towards the exit and then saw more people and someone said that there was a person with a gun. Shit. — 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

Police cruisers pull up, hopped out with rifles ready and I told them where the situation was as I headed down the street to meet up with a couple team members. — Todd Sherman (@tdd) April 3, 2018

Information available via Citizen said police have cleared the first, second and third floor and that the suspect may have shot him or herself - though this has not been confirmed.

Active shooting at YouTube. This latest update is from the Citizen app. pic.twitter.com/TRFyx1xWvU — #NastyWoman (@DeeBeeThak) April 3, 2018

According to unconfirmed reports, police have swarmed the property where two people have been shot so far.

Police could be seen outside YouTube HQ frisking and searching evacuees before letting them go to make sure they aren't the shooter or involved in the shooting.

Police haven't released much information yet. But a KTVU reporter talked with a witness who said they are evacuating nearby buildings and is affecting businesses across the office park where YouTube HQ is located. However, Connie Jackson, the San Bruno city manager, said no other businesses had been impacted.

Another witness said the shooting began at some kind of party inside the building. The shooting allegedly began inside YouTube HQ. The witness said he heard or saw three people shot, including one woman whom he said died after being shot multiple times with "no mercy."

San Francisco General Hospital has confirmed that they have received between three and five patients. Stanford hospital has said it has received four or five patients. Neither hospital released any information about the condition of the victims.

A witness told KTVU said she heard a series of gunshots from her backyard which is near the office park where the YouTube headquarters is located. She described the shots as happening in clusters, with successive rounds sounding further away.

Her husband reportedly saw people running out of the HQ with their hands up.

A witness who works at the nearby Carl's Junior helped treat a young woman who was shot in the left leg, and used a tourniquet to stop the bleeding. Several other witnesses described her limping into the Carl's Junior. At a different nearby restaurant called Hashes and Brews, three victims fled there one had been grazed by a bullet, one had been shot in the ankle, and another in the leg.

The shooter at YouTube is really fucked, but we might finally get some female representation in the mass shooting movement! pic.twitter.com/BqQ3MUxKkQ — liam liam liam liam liam liam liam liam liam liam (@StilILiam) April 3, 2018

Live feed:

Google's communications department said it would relay information as soon as it becomes available.