SCROLL DOWN FOR MULTIPLE UPDATES.

At 12:57 p.m. Pacific time, YouTube executive Vadim Lavrusik tweeted that there was an active shooter at the company’s headquarters in San Bruno, CA, and that he was barricaded inside a room with coworkers. (UPDATE: No longer active. See updates below.)

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

A few minutes later, San Francisco news station KTVU tweeted a confirmation.

BREAKING: Active shooter situation at YouTube headquarters https://t.co/htXgPLFSii

— KTVU (@KTVU) April 3, 2018

There are police surrounding the @YouTube building – potential shooter. Be safe! pic.twitter.com/4JTKkn3Oy1

— Erin (@erinjeanc) April 3, 2018

Twitter reports multiple ambulances arriving on the scene. We will update this breaking story as more information becomes available.

UPDATE, 1:14 P.M. Pacific:

An employee describes the fire alarm going off, then as employees started evacuating, other employees running and warning of a shooter.

https://twitter.com/MrWillToLive/status/981260734305918978

People in nearby offices posted photos of employees being led out with their hands up. Reports say there is a female shooter inside.

We are seeing @YouTube employees being brought out with hands up! pic.twitter.com/ZlSMY9FIVm

— Erin (@erinjeanc) April 3, 2018

UPDATE, 1:30 PM Pacific:

The Associated Press has confirmed. Fox News is also reporting that more than 50 calls to 911 were placed.

BREAKING: City manager of San Bruno, California, says multiple 911 calls are reporting a shooting at YouTube headquarters.

— The Associated Press (@AP) April 3, 2018

Multiple shooting victims being treated at a hospital, reports @KTVU.

— Steve Herman (@W7VOA) April 3, 2018

WATCH live helicopter feed here:

https://twitter.com/Tech_Pug/status/981269902999748608

UPDATE: 1:55 PM Pacific

Witness tells KTVU the shooting happened at a YouTube employee event or party and describes a victim being shot “multiple times” and another being shot “10 times.” He did not see the shooter.

UPDATE: 2:15 pm Pacific
A YouTube employee describes “blood drips on the floor”, via Fox.
https://twitter.com/tdd/status/981262648867143680

UPDATE: 2:21 pm Pacific
Oh boy:

WATCH LIVE: Shooter at #YouTube in #SanBruno believed to be white female adult wearing dark top and headscarf. https://t.co/U5RwzFfya6 pic.twitter.com/NFG8MP7MdZ

— ABC7 News (@abc7newsbayarea) April 3, 2018

UPDATE: 2:21 pm Pacific
More from Andrea:
“She was shot in the leg” … Eyewitness Describes YouTube Shooting Scene to Fox Reporter (VIDEO)

UPDATE: 2:29 pm Pacific
BIG UPDATE, SHOOTER DECEASED

BREAKING: Female shooting suspect near YouTube headquarters is deceased at the scene, law enforcement sources tell @NBCNews. https://t.co/rDzWIBw0Wr

— CNBC Now (@CNBCnow) April 3, 2018