Of course, the first thing I see are folks going, 'Well, if they just banned all the guns then nobody'd ever commit suicide!'. It is a shame what happened to this kid, but the reality of the situation is that if he really wanted to kill himself, he could have EASILY found another way to do it. Unless you guys have also banned high bridges and sharp implements, this one situation is about as good an argument for gun control as wanting to ban cars because of the vastly greater amounts of people killed by them every year.
I don't know what happened. I'd agree with earlier posters - it seems like he was probably being bullied and decided to get back at everyone that way. Unfortunately, the logic of a suicidal teenager is rarely sound. He needed help and support, which he didn't get.
That's assuming that's what happened. I am REALLY curious how a 14 year old would be at an elementary school, because I was 14 my freshman year in high school. A lot of odd things here.