Underground disaster shelters for 4 to 400 troops/people designed by the engineer who wrote the book on using underground shelters to provide protection from nuclear fallout radiation. NORAD shelters are specifically designed to protect occupants from nuclear, biological, chemical (NBC) and electromagnetic pulse (EMP) attacks; as well as natural disasters such as earthquakes, typhoons, cyclones, monsoons, tornadoes, hurricanes, floods and wildfires.