^^^
I have harbored fears of Jihadi attacks on our schools for a long time. They want to hurt us where it hurts the most. That would be our young and schools are where they are easily found, and stupidly, those schools are big, fat, plump, soft targets very often undefended and ripe for picking by terrorists. They are even No Gun Zones inviting attack.

The obvious preventative is hardening the targets, as the Israelis have done. I’ll wager the Chechens have done the same now too. Make them less inviting to whomever, including Jihadis and homocidal lunatics. It can never be foolproof, but that is no reason not to get busy...now. There are over 200 million guns in this country. Trying to neuter them as a defense is asinine and guns are not even the biggest threat. Check out what happened at a school in Bath Township, Michigan in 1927.

https://en.m.wikipedia.org/wiki/Bath_School_disaster