Local hospitals confirm they are treating people.
UPDATE: A female suspect has been found with an apparent lethal self-inflicted gunshot wound.
It is being reported that there is an active shooter at the YouTube headquarters in Northern California this afternoon.
There have already been injuries according to nearby Stanford Health Care. The hospital confirmed that they are treating four to five people involved in the shooting, but have not released details of their condition.
Brent Andrew, spokesman for Zuckerberg San Francisco General Hospital also confirmed that the trauma center is currently receiving patients from the shooting.
Staff used social media to update people on the situation, tweeting that they had barricaded themselves in rooms and there was a shooter in the building.
One YouTube employee, Todd Sherman tweeted that he was in a meeting when there was a great commotion, he thought it was an earthquake but in reality, it was people rushing to safety.
ABC helicopter coverage showed people coming out of the building with their hands in the air.
The San Bruno Police Department tweeted out a warning that people should stay away from the area.
There are about 1,700 people who work at the campus.
Local FBI agents are monitoring the scene.
Google which owns YouTube tweeted out that they are “coordinating with authorities and will provide official information here from Google and YouTube as it becomes available.”
This is a developing story.