I remember, in the 60's, practicing "Air Raid" drills too. The siren would sound and we would all exit our classrooms, head to the lower level of the school, line up along an interior hallway and assume the "protected position" which was squatting on the floor with our chins to our chest and our arms covering our heads. The air raid shelter area in all schools were marked with a yellow and black symbol.
Wow! that memory was a blast from the past!