This girl was 15 years old and suicidal. She didn’t end up this way overnight. Could anyone have predicted that she could do such a thing as being a school shooter? Probably not, but I suspect the parent(s) should have at least known she needed help. Was she bullied or just depressed? Either way, I would have noticed a change in my child. I think even teachers can notice behavioral differences. Am I placing blame here? Not convincingly, but I think we should all be aware of mood swings and attitude in general, especially people we are in contact with on a daily basis.
Someone hell bent on taking their own life is almost impossible to prevent. It’s a shame they have to commit a heinous act like this instead of just going through with the inevitable.