I've had a few horrible mishaps:
-As a little kid, I had this old book of children's poetry that I loved. It was probably published sometime in the early 1900s. Well, I was carrying it around with me one day and left it outside. And then it rained. Needless to say, my parents were very displeased at the result...the poor book was ruined!
-At one of our old apartments, we had a lack of bookshelves, so I kept a lot of my favorite paperbacks in a box in the closet. After being gone for two days, we came home and discovered two inches of water in the bathroom and the closet (which was in the bathroom). It turns out, the neighbors upstairs had been running their washing machine, which hadn't been installed properly, and a cascade of water had entered our apartment...right on top of my box of books. It just so happened that their washer was directly above my cherished novels. They were all waterlogged and ruined, and the apartment people never even apologized.
-I think I have spilled pizza sauce, Coke, and iced tea on at least 50 of my books. I can't help myself.