My Mrs would leave her purse with the gun in it sitting in the library or somewhere and a kid would get the gun and play with it.
I would not be against training and arming some teachers who have aptitude for it and possbily already are experienced with guns.
But arming all of them is not a viable idea.
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.

[SIGPIC]
..I also have a 427 Cobra replica with an aluminum chassis.