YouTube's headquarters in San Bruno is still considered an "active event and investigation" following a shooting incident on Tuesday. According to San Bruno Chief of Police Ed Barberini, three people were shot and one is dead from a possible self-inflicted gunshot wound.

Barberini told gathered press that, following "numerous 911 calls" received at 12:46pm local time, San Bruno police arrived on the scene minutes later to find one victim with an apparent gunshot wound near the front of YouTube's official building. After that, the police's search turned up a female victim dead via a "wound that may have been self-inflicted" inside the building. Two additional victims were located several minutes later at adjacent businesses.

The building has since been fully evacuated, according to Barberini. The press conference did not include confirmation on names of victims, the type of weapon used, whether the dead woman on the scene was the sole shooter, or what relationship the woman had with YouTube and its staff.

“X-ray down” with “gun recovered”

"We are responding to an active shooter," the San Bruno Police Department tweeted on Tuesday afternoon. "Please stay away from Cherry Ave & Bay Hill Drive." That's the location of YouTube's San Bruno offices.

Before the city's official press release was released, a San Bruno dispatch call during the active shooting described an "X-ray" suspect (a dispatch code for female) "down" with a "gun recovered" and an indication of an ongoing hunt for a possible male suspect. San Bruno's city manager later issued a statement claiming "no further threat to the community" as of 2:19pm local time.

"Active shooter at YouTube HQ," tweeted YouTube staffer Vadim Lavrusik just before 1pm local time. "Heard shots and saw people running while at my desk. Now barricaded inside a room with coworkers."

A photo from the scene showed a swarm of emergency vehicles outside the building:

Another staffer described the situation as "surreal."

I got evacuated outside with my hands up. I’m with other people. I don’t think the shooter’s been found that I know of. I saw blood drops on the stairs I walk up everusay. I’m shaking. This is surreal. I hope my colleagues are okay. — Lil | Milktea (@_lilchen) April 3, 2018

Local television station KTVU says that three patients—two female, one male—are being received by San Francisco General Hospital. The unnamed male victim, a 36-year-old, is described as in "critical condition." Earlier reports hinted at that nearby Stanford Hospital was expecting additional victims, but a Stanford spokesperson later clarified to Ars Technica that the hospital expects "no [YouTube-related] patients at this time."

Hollywood Reporter staffer Ryan Parker was the first to report that "people had been killed on scene," and he attributed that statement to San Francisco General Hospital PIO Brent Andrew. The rep did not confirm a number of casualties at that time.