You can't stop someone flipping out and hurting people, but in this case it could have been a whole lot worse had he used a gun. At least with a knife you have a chance to fend off your attacker as they have to be in close proximity to the victim. Unless they are some kind of ninja knife throwing maniac. If he'd strolled down the hall popping people off from 20 feet away with a pistol or automatic weapon, you have less of a chance. A gun is deadly in the wrong hands and allows a very quick and effective way of killing people as we know from all these shootings that seem to be happening. Of course the real question is why are these kids doing this? What on earth is the society doing to put this sort of action in their heads? Mental.

Hopefully the injured people will recover without a fatal outcome. Finger crossed muckers.