When I was a little kid in grade school, and we had to crawl under our desks in case of a nuclear bomb. We practiced them like fire or tornado drills.
I did 1st grade in 59/60. I "think" I remember something like that, but it could be the influence of seeing the newsreels.
I do remember holding hands when we left on firedrills. And (are you listening Charlie Brown?) the little red-headed girl DOES exist!