I was in Port Arthur, TX in the 50s. With our proximity to Houston and surrounded by refineries we had those, under the desk, drills. I still have the dog tag I was issued with my blood type.
That’s what people don’t get who mock desk drills. It was for people like you who were a survivable distance outside of the blast zone. Kids were under desks to protect them from flying glass from the shockwave. And to give little kids a sense of security and the sense that the adults were in control of the situation.