When I was a kid (1972 for example)....if you had come around and gotten everyone hyper over security in the school, we would have been in a daze for about an hour or two.
Protocol's? Some guy from the county board would likely have to come out and explain the word to both the teachers and students.
We had two vets on the teaching staff. One guy was a WWII vet, who claimed to have taken down a bunch of Japanese guys in the war. He was a bit of a nut, but I imagine that he could handle a .45 if necessary. The other guy was a Nam vet and I'm pretty confident in saying that he'd handle a .45-caliber.
The bus drivers? I'd take a humble guess and say they'd all have double-barreled twelve-gauge shotguns by their left side....ready to swing them around at any character acting crazy.
Every single boy in the school likely had a three-inch knife in their pocket and could have come out with a blade in less than eight seconds.
From the community? There would have been forty folks at the front door of the school within five minutes....who had various weapons in their cars or homes. They would have even beat the cops to the front door.