Crowds occur frequently, usually without serious problems. Occasionally venue inadequacies and deficient crowd management result in injuries and fatalities. Major crowd incidents are described. Extreme crowding results in individual loss of control, and both psychological and physiological problems. A simple model with the acronym "FIST" is proposed to provide a basic understanding of crowd disasters. The acronym elements are defined as the crowd Force (F); the Information (I) upon which the crowd acts; the physical Space (S) involved, both in terms of individual density and larger scale architectural features; and Time (T), the duration of the incident. The model is used to illustrate crowd characteristics and to develop guidelines for the prevention of crowd disasters. It is concluded that real time information and communication are key factors in preventing crowd disasters. The formal certification of crowd manager for venues of 500 persons or more is recommended.
revised for crowdsafe.com, January 2002