This case interests me because it reminds me of an old friend, who went from "seemingly normal" to "psychotic" in the relatively short time that I was close friends with her. Looking at Elisa's tumblr and internet presence, she reminds me a lot of my friend. Especially after watching the elevator video. From my perspective, it appears that Elisa is hallucinating, talking to herself, seeing things that aren't real, and looks very scared, or at least confused.
The hints that my friend was becoming psychotic were subtle, mostly just involving weird beliefs/statements (that were only really weird in retrospect), seeming dissociated or depressed, etc. Next thing I knew she was taking off her clothes in public and saying she controlled the universe. She eventually got committed because she pulled a fire alarm and crawled, naked, into a stranger's car. Yes, it makes absolutely no sense, much like Elisa ending up on the roof of the Cecil and somehow getting inside the water tank.
I don't mean to derail the thread -- but from my research and personal experience, you just cannot trust people in the midst of a psychotic episode to make decisions that are anywhere close to sensible. Not only that, but people who appear sane can become psychotic in the blink of an eye. They will do things that you thought were impossible, or that no human would do. I would imagine that Elisa was scared, or maybe even just curious, and got into the water tank without an inkling of what it actually was or the danger it presented to her.
My friend is lucky that she did not die because many of the things she did brought her dang close. She would eat random pills off the ground and get into complete strangers' cars. Her mindset reverted to that of a naive child who didn't know left from right, when she had been very intelligent before.
Schizophrenia or psychosis is such a tragic thing. When a person is psychotic, they become completely different from who they once were. It's terrifying to see, especially since nothing you say gets through to the person at all, as they are off in their own world. Rest in peace, Elisa.
All MOO.