Thanks everyone! Yeah my boyfriend is soo good... he went out and picked up the pieces (literally) and buried her in the woods beyond the backyard. Since we don't know if something wild got into the backyard or if it was my brother's dog who got to her, my boyfriend feels sooo guilty since he left the house and left my brother's dog in the other fenced in yard. Its just terrible though.
Every night I make my boyfriend go with me to let the dogs out since I am nervous something is getting in yard and it's big enough to do what it did to my bunny, then its big enough to do that with one of my dogs. I see her empty cage now and it's sooo sad.
Maybe someday I'll get another bunny, but right now... I don't think so.