This chapter examines responses to severe stress at the individual, community, and mass levels. The social and behavioral sciences, and their cognate helping professions, have long functioned with the assumption that traumatic-level stressors cause significant psychological damage to most, if not all, people who endure them. Concepts of indomitability, resilience, and posttraumatic growth challenge that orthodoxy, and are increasingly being supported by the evidence. In the chapter, I discuss such stressful events as major accidents, natural disasters, war, and genocide, and present data that affirm human strength.