Yes, words are deadly, and they can kill.
The 12 year old who took her own life must have felt so desperate to get away from the bullying, and her parents should have known what was going on, but you are right, they have suffered enough, having lost their little girl.
The parents of those who bullied her should be made to answer, though, and their children should be punished, although I am not sure what kind of punishment would be suitable for children like that. You could expel them but that won't solve anything.
Most schools these days have an anti bullying policy in place, so it is sad that things like this still happen - makes me wonder whether these bullying policies are actually enforce, or there just for show.
If words could kill you would have been dead. The fact that, despite the bullying, you aren't, proves that it wasn't words that killed that girl. She was crazy, and killed herself.
True, but I was older than this girl and perhaps better able to cope - she wasn't. Not everyone can cope.