My neighbor used to build nuclear bomb shelters. I am not kidding. He would sell you one if you desired. He was the guy you just described. He was a zillionaire and died in a plane crash at 89 years old last year.
"...In the 2000s, Brown also became known for building a nuclear shelter across the street from his home. ..."
http://www.centuryinter.net/tjs11/jean/brown10.htm
"...Modock said Brown’s main concern throughout his life was some kind of military or biological attack on the U.S. According to Modock, Brown bought land in Greenland and intended to fly his family there if such an attack ever occurred.
“It’s ironic he died in a plane crash and not from an attack,” Modock said. ..."
http://chronicle.northcoastnow.com/2010/01/25/barber-recalls-inventor-don-browns-creative-mind/