Or: https://en.wikipedia.org/wiki/....School_attacks_in_Ch

One of the things that blaming 'mental illness' fails to capture is the deeper truth that 'modern' society itself is toxic. That some people cannot cope is almost akin to the observation that people often respond to a drug differently. We are all 'drugged.' Some of us experience less severe symptoms, and others are receiving superior 'treatment,' but it is 'modernity' itself, in its current incarnation, that is making people 'ill.' It is clear that there has been a change in our societies from, say, the 1930s, to the present. There were knives, and there were guns, prior to the 1950s, but mass murder in schools was not a 'thing.' So what changed? The society got more toxic, that's what changed. What to do about it? Get rid of the knives and guns, or change society? Well, the former will achieve nothing, and the latter, to be frank, is not going to happen without some kind of serious shock to the system. (This will almost certainly be extremely bloody.) So, in the meantime, we must defend ourselves from the ones that would disarm us (these themselves being very sick people), and try to counteract the toxic trends of our civilization in an aggressive and proactive manner.

Good luck.