Massive sinkholes devour whole city blocks with no warning. A woman falls through the ground in her backyard and is almost buried alive. An unsuspecting driver suddenly feels the road give way beneath him and plummets into an abyss. It’s not just the stuff of horror movies and headlines – it can happen anywhere to anyone. In this 1x60 special, National Geographic breaks down the science of sinkholes, tells harrowing stories of survival and takes viewers beneath the ground on a hair-raising journey through an underwater cave system to better understand what causes these terrifying freaks of nature. We will also create our own “sinkhole” simulations demonstrating the impact on a human body when it suddenly falls anywhere from 16 to 60 feet whether in a car or in free-fall. Ultimately, we will learn if it is possible to survive one of Mother Nature’s most effective death traps.