Many participants and observers have analyzed the 1996 Mount Everest tragedy, and blamed a host of factors including the weather, equipment failures, and human error. This analysis examines the people and events through three theoretical lenses: behavioral decision theory, group dynamics, and complex systems. The research findings suggest that factors at each level individual, group, and organizational system interacted with one another to cause the tragedy. This analysis provides a framework for understanding and diagnosing large-scale organizational failures, and it provides several important lessons for managers making and implementing high-stakes decisions within organizations.