This group consists of people who live in tornado, hurricane, flood, wildfire, earthquake or heavy snowfall-prone areas and want to be prepared for possible emergencies. They invest in material for fortifying structures and tools for rebuilding and constructing temporary shelters. While assuming the long-term continuity of society, some may have invested in a custom-built shelter, food, water, medicine, and enough supplies to get by until contact with the rest of the world resumes following a natural emergency.
Firearms instructor and survivalist Colonel Jeff Cooper wrote on hardening retreats against small arms fire. In an article titled "Notes on Tactical Residential Architecture" in Issue #30 of P.S. Letter (April 1982), Cooper suggested using the "Vauban Principle", whereby projecting bastion corners would prevent miscreants from being able to approach a retreat's exterior walls in any blind spots. Corners with this simplified implementation of a Vauban Star are now called "Cooper Corners" by James Wesley Rawles, in honor of Jeff Cooper. Depending on the size of the group needing shelter, design elements of traditional European castle architecture, as well as Chinese Fujian Tulou and Mexican walled courtyard houses, have been suggested for survival retreats.
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.
Hate to break it to you, but your dog probably has a better chance of making it through a total societal collapse than you do. A quick Internet search of "dog survives" lists everything from drowning to being shot, from bear attacks to war -- whereas the closest you've ever come to "surviving disaster" is getting your wisdom teeth pulled, and even then it was only with the help of a cadre of trained medical professionals and a carton of the strongest painkillers on Earth.
OK. Great. You've stockpiled for the end of the world, you quack. The chances of the world ending are smaller than ... holy crap, what the hell is a supervolcano? See why we're all doomed in 5 Ways The World Could End That You'd Never See Coming. And if that's not enough to get you to build your own bunker, check out 6 Tiny Mistakes That Almost Ended The World. Really, the planet almost ended due to a blown fuse? Come on humanity, let's get it together.
Every year in the US about 150 people die while out and about in national parks, more than 1,000 die in hunting-related incidents and thousands of backcountry enthusiasts get in deep trouble and require a Search and Rescue team to save them; with dozens of those folks dying while awaiting rescue. Most fatalities are the result of poor preparation. Bad weather descends and people get lost. They wander without water or shelter, often injuring themselves in the process. If they survive they often suffer frostbite, hypothermia, dehydration, trench foot or some combination of them all.