How were people still in there so recently?

I don't know :) I took another look at the building yesterday (it's on my way to work), and the its foundations still look solid. So, if there is something to collapse, it could be the balconies.

Abandoned asylums are the dream of every urbex photographer :) But I supposed you could get in trouble if you encounter some of those people that sell drugs and stuff.

Thanks for your comment, Mark!