While I was in school, I did a lot of odd jobs helping friends and what not.. One of my buddies used to do custom home audio, outdoor audio and home theater systems.. He specialized in retro fitting with older homes.. This area where we were working had a lot of "old" money.. Mostly older Jewish folks or the plantation owner types.. I was amazed to see that just about every one of those homes had a bunker or bomb shelter of some sort.. I was trenching one day so I could lay some conduit in the ground for some data/speaker cables (these were the days before wireless networking and wireless speakers were standard fare like today).. I ran into what looked like the top of a shipping container.. Did some more digging, and eventually found the top latch for the door (this confirmed my suspicions)... So, yeah, someone actually took a shipping container and buried it, intending to use it as a bomber shelter.. The "new" owners were a younger couple with 5 kids or something.. I told them what I found and they freaked out!! They were extremely angry that the previous owners did not disclose this... It's strange because you'd figure a bomb/fallout shelter would be more underground.. I only trenched 12in. and hit the top of it.. Also, I'm at a loss of how you entered the thing.. Maybe there was a top hatch or something.. But yeah, I used to run into that stuff all the time while working in that area..