I believe it can be traced to the socialist influence in America in the 1950’s and the “Better Red than Dead” philosiphy.
My daddy built us a fall-out shelter. It felt good knowing that he loved us that much.
I remember asking him—while he was cementing in bricks—what would happen if the bad guys broke in through the entrance. He looked at me and said, “I would shoot them.” I was so surprised. I was also proud and secure.
The people who later (much later) purchased the land filled it in. I’ve never been able to understand that.