This book is the biography of a deadly avalanche, detailing how a combination of factors--steep, open terrain, an unstable winter snow pack primed to slide, aggravating weather conditions, and a trigger provided by a handful of back-country skiers--resulted in human tragedy. It is the story of a particular avalanche, but it illustrates a natural phenomenon that has threatened human endeavours throughout the world since people first ventured within the reach of steep snow slopes.