Generally the reason most people focus their attention on these type of events is because schools are where parents send their children to learn and be safe. Of course that is ideal, bad things can happen anywhere, but it just seems as if this sort of "taking revenge on former schoolmates" is becoming more and more popular. It's happened 3 times in my city alone, and already today, some kid brought a fake gun to school just so he could scare everyone and get attention.