Some evangelical Christians hold to an interpretation of Bible prophecy known as the post-tribulation rapture, in which the world will have to go through a seven-year period of war and global dictatorship known as the "Great Tribulation". Jim McKeever helped popularize survival preparations among this branch of evangelical Christians with his 1978 book Christians Will Go Through the Tribulation, and How To Prepare For It.
In both his book Rawles on Retreats and Relocation and in his survivalist novel, Patriots: A Novel of Survival in the Coming Collapse, Rawles describes in great detail retreat groups "upgrading" brick or other masonry houses with steel reinforced window shutters and doors, excavating anti-vehicular ditches, installing warded gate locks, constructing concertina wire obstacles and fougasses, and setting up listening post/observation posts (LP/OPs.) Rawles is a proponent of including a mantrap foyer at survival retreats, an architectural element that he calls a "crushroom".
With the world seeming to become a more volatile and dangerous place with every encroaching year, it can be hard to know exactly where you can feel safe. The modern media is overloaded with stories about violence, crime, and sensational pieces on the worst people in our society. But there have to be some places within the United States where the chances of anything like that happening to you is next to impossible, right?