This story is disturbing as hell. It's all the rage on 4chan and other paranormal boards as of late.
My take: she's obviously
on something. They say tests didn't show anything in her bloodstream, but who knows what she took, and if it would show up on whatever tests they did? Also, I'm not sure how being submerged in a water tank for a week would affect said tests. And the reason the doors don't close is because she hit the "doors open" button in her disoriented state.
So I think she was on something.
But then comes the disturbing thought... that somebody working in the hotel killed her. Considering the water tanks were impossible to just wander in to. And consider that maybe she wasn't drugging-out for recreation but was in fact given something akin to date-rape, and then you get to thinking.
Or, perhaps she just played the elevator game:
This has been all the rage, too, and I just learned about this the other day. I've been so interested in it I think I'm going to write a short horror story based on the urban legend—not the news item—for Halloween.