First broadcast on NBC, this documentary contains fearsome footage of the dynamic power of raging snow showing how its force can snap trees as if they were twigs, reduce houses to rubble, and kill anyone unlucky enough to stand in the way. This exclusive program includes chilling firsthand accounts and terrifying stories of being buried alive. Amazing photography - watch as a wall of white roars forward, then stops short just feet from the cameraman. Learn the danger signs of an avalanche, and find out what to do if you're caught in one. Fly with the experts who drop explosives on snow-laden mountains to study made-to-order avalanches. Relive some of history's worst avalanches, including a deadly American tragedy in Washington State. (60 minutes)