Kansas underground shelter

This artist rendering released by Vivos, an underground shelter network, shows a design for an underground bunker. Spike TV will be airing a six-episode series called "Last Family on Earth" a competition in which survivalists will compete for an underground bunker in an undisclosed location. The series will air in the fall. (AP Photo/Vivos via Spike TV)
This artist rendering released by Vivos, an underground shelter network, shows a design for an underground bunker. Spike TV will be airing a six-episode series called "Last Family on Earth" a competition in which survivalists will compete for an underground bunker in an undisclosed location. The series will air in the fall. (AP Photo/Vivos via Spike TV)

Robert Vicino is creating what he calls the world's largest private underground survivor shelter --  the Vivos Survival Shelter and Resort -- using a complex of limestone caves dug more than 100 years ago beneath gently rolling hills overlooking the Missouri River. (AP)