Though I understand that "Its not the gun, its the person holding it" claim, Im all with Gen on this.
Im sure its the same in the other countries, as it is with Aussie, but its hard to get your hands on a gun here unless youre connected and have big $$ to spend (Illegally) or go through a long process of obtaining a licence and spending big $$$ to make sure you have all the neccessary controls in place to keep that gun safe and out of the wrong ppls hands. Ive run into some bat shit crazy ppl high as a kite that have gone to lenghts to run ppl off the road, or get out of the car and want to punch on, drunk as all shit and mouthing off to gangs/groups of ppl. I could only imagine a nation, with the same sort of rage or delusion with a gun in their hands 
Its also the "sane" ppl defending their right to own a gun most of the time, but truth be told everyone has the possiblitiy to break at some stage or another also. With gun control in place it does make it a lil harder for events like this to occur as often as they do in the States.
This is just tragic though, I couldnt imagine being connected to this, or if my kids had of gone to that school etc...
"I lie down next to an angel, fall asleep and fly with the demons"
I once prayed to god for some planets, but quickly found out he didnt work that way