A woman shooter is always a surprise. Few details so far, though:

A female suspect in a shooting at YouTube’s headquarters is dead, NBC News reports…

A spokesperson from Zuckerberg San Francisco General Hospital confirmed that it received patients with gunshot wounds from the incident but could not give a number because it was “still receiving patients”

Stanford Health Care told CNBC that it was expecting four to five patients, with no report on their condition.

There are 1,100 employees in the building. Gulp. The shooting began over an hour ago but thus far information is scarce: News outlets are mostly just recycling tweets from YouTube employees describing the moment they heard the shots and began evacuating. This tweet from around 4 p.m. ET also suggested a female shooter, though, long before NBC began reporting it.

The police are promising a press conference at any time. It’s still Too Soon For Politics but by tonight the usual questions will emerge: What type of gun was she carrying, a good one (revolver), a bad one (semiautomatic), or a very bad one (semiautomatic rifle)? Did she purchase it legally? Were there “red flags”? Stand by for updates.

Update: Ah, I see that some lefties are already leaping to connect the shooting to YouTube’s recent crackdown on instructional videos posted by gun owners. There’s zero evidence of that so far, but as Alex Griswold says, that never stopped them from blaming Sarah Palin for the Gabby Giffords shooting.

Update: This doesn’t sound political at first blush: “A federal law enforcement official told The Daily Beast that a woman shot her boyfriend at YouTube headquarters in San Bruno, California on Tuesday. The assailant is dead, the official said.”

Obviously she shot more than just her boyfriend, though. That press conference is coming.

Update: The latest:

Update: Yeesh. Never trust Newsweek.

Update: MSNBC says the shooter approached a table at which people, presumably including her boyfriend, were having lunch and opened fire. Separately, doctors at San Francisco General Hospital say that they’re treating three people — a male in critical condition and two females, one in serious condition and one in fair condition. If in fact this was a “domestic” incident in which the boyfriend was targeted, it remains an open question as of 7 p.m. ET whether the two women were targeted too or just collateral damage.