Since yesterday I have gotten about 5 search hits (all from the UK) for "what's the name of the sister of the wicked witch who gets squished by a house" or "what's the name of the wicked witch who gets squished by a house in Wizard of Oz." Obviously this is some kind of weird assignment and I am all about helping, so I will help you guys out.
Elphaba Thropp is the name of the wicked witch. I can't remember her sister's name and I have loaned the book to someone, but I'm sure you can find a synopsis online. The book is called "Wicked." (Come on, you don't expect me to do ALL the work for you, do you??)
OH FINE. Look in Wikopedia. I have done ALL the work for you, you slackers.
This reminds me. I need to ask for that book back. She's had it for months.