The Home Depot, Grainger, Atlas Survival, The Survival Center and Ultimate Bunker sell underground shelters. The shelters available come in a wide variety of shapes, sizes, construction materials, features and prices. There are basic storm and tornado models for short term stays that can accommodate families as well as large groups. There are also long-term habitats that are built to protect occupants from major calamities such as nuclear and biological war, terrorist attacks, forest fires and many other apocalyptic events.
Grainger and The Home Depot sell storm shelters that can fit from four to 63 people. They can be installed underground, and some can be bolted in other places as well. They generally have basic seating with outside ventilation that passes through limited internal filtration.
Atlas Survival, The Survival Center and Ultimate Bunker supply underground shelters for more drastic needs and longer occupation. These type of systems have living rooms, kitchens, baths and sleeping quarters. Sophisticated air filtration systems, water supply storage, solar power, shortwave radios and external camera surveillance options are available. All of these companies custom manufacture shelters to suit customers needs or fears, and some come stocked with food supplies.
Atlas Survival claims that its design is the only one that has actually been tested to survive a nuclear blast, citing a joint experiment with the U.S. Army Corps of Engineers in 1959 that used live volunteers during a nuclear bomb test.