Gun free zones aren’t safe. The bigger the population the more detached people become amongst all the other problems.
They don’t want people at work with guns for something like that for fear it could wind up someone like the shooter.
They have bulletproof inserts you can put inside back packs, backpacks that convert to vests, under shirt bulletproof on and on. Something to consider but the weight and not protecting all of them discourages people.
I’m considering getting the inserts for the grandkids.