Despite not having mental institutions (or the ablist idea that people with mental health conditions are dangerous whent they're more likely to be abused not be abusive) or armed schools in other countries, this is an America specific problem. Prevention is looking into why, not just reacting to the problem as though it'd a thing that we should just accept as the new normal.Prevention? You mean like putting the crazy people back in institutions? Ok that too.
Having armed people already in schools to stop shootings is prevention.
Like maybe addressing the US growing wealth inequality, lack of federal gun control, lack of access to social services, wildly expensive healthcare, and other reasons everyone laughs when nationalists cry 'America is #1'.