Sad thing to happen, especially close to home (MN, 1 hour away). It'* hard to tell who is at the verge of snapping sometimes.
Personally (and this is just my opinion) there are too many people worried about what they an and can't do to raise a kid that they forget what they need to do. Not saying that it is entirely the parents fault for this, but also those around the person who see what goes on to this person and allows it to continue thinking it is all in jest.
I have had people who severly pissed me of when I was in high school too. Like most people I was able to blow it off and go on with my life. It just wasn't worth dealing with them if I cna do so much better by forgetting about it. It'* just a shame that not everyone can deal with what life gives them.