The story of one man who survived a deadly avalanche on Mount Everest in 2015 is breaking his silence in a new documentary. Michael Churton was in the thick of it as a wave of ice, snow, and boulders came barreling at him. The lethal avalanche was triggered by an earthquake and claimed the lives of 200 people. His story is featured in the forthcoming Smithsonian Channel documentary, "Nightmare on Everest." Despite what happened, Churton said he would certainly go back.