Abstract----- The Bethnal Green tube shelter disaster, in which 173 people died, is a significant event in both history and psychology. While notions of “panic” and “stampede” have been discredited in contemporary psychology and disaster research as explanations for crowd crushes, Bethnal Green has been put forward as the exception that proves the rule. Alternative explanations for crushing disasters focus on mismanagement and physical factors, and lack a psychology. We analysed 85 witness statements from the Bethnal Green tragedy to develop a new psychological account of crowd disasters. Contrary to the established view of the Bethnal Green disaster as caused by widespread public overreaction to the sound of rockets, our analysis suggests that public perceptions were contextually calibrated to a situation of genuine threat; that only a small minority misperceived the sound; and that therefore this cannot account for the surge behaviour in the majority. We develop a new model, in which crowd flight behaviour in response to threat is normatively structured rather than uncontrolled, and in which crowd density combines with both limited information on obstruction and normatively expected ingress behaviour to create a crushing disaster.