Your childish statement doesn't deserve a response.

This kind of thinking comes out of a mind that has been conditioned to believe that the nanny state will protect you. You don't need to take care of yourself, because the nanny State will do it for you.

If you think that the police will protect children in such an event, you are sadly mistaken.
Police rarely prevent such events from occurring. The police usually show up after the event has already taken place.

An armed & well trained public is the answer. It would work much better.

If at least one of the adults that were present on the scene had a concealed carry, then it could have quickly quelled the outburst.

The same nanny state (& the philosophy that such people are in support of) is more than ready to put young children on drugs so they, & the teachers in the public school systems, will not have to deal with the natural expression of emotions. To ensure proper mental health & well-being, the allowance of emotion expression is paramount. The State creates the problem in the first place, with the prescription of medications that subdue the psyche of the child at a young age, so the society (the mainstream teaching methods in the classroom) will not be interfered with.

Drugs doses tend to be increased over time due to biological tolerances that the human body will build up.
Its only after some years, that the unexpressed emotions build up internal pressure and it crescendos, as the flood gates ultimately break open, and the wild torrents of emotions become overwhelming (how long can you continually keep your fist clenched?). All it takes is to have one's skin scratched for the damn to burst forth uncontrollably. And the perverted internal wrath to affect others that are within close proximity.

All it takes is to understand one's own emotions & the workings of one's own mind to see where the root cause lay.

Are you willing, do you have the courage, to look at your own self-created demons that lay within?