Last month, #*IT Happens reported on the cancellation of Justin Bieber's Sydney concert due to fears of crowd crush. This month, we go deeper into the issue, and present a model which is useful in understanding crowd behaviour and the causes of excessive crowd density and crush. It was developed by Dr John Fruin, world reknown expert in the area of crowd behaviour and dynamics. It is known as the Fist Model: Force, Information, Space, Time. Force

The force created by the dynamic movements of a crowd can result from pushing and pulling in any direction. They create potentially unsafe pressure loads within a crowded space. Dynamic crowd movements, combined with excessive crowd densities (below 0.28 m²) can create dangerous forces upon the human body, including haemorrhaging and mechanical asphyxia.


This relates to audible and visual messages provided to the crowd, which affect individual perceptions and reactions to the environmental stimuli presented to the crowd. By providing a lack of accurate and timely information to a crowd, the event organiser can invoke an undesirable response from the stimuli presented. These may be based upon the patrons' perceptions of a risk rather than the real risk.

For example, if a person in a crowd sees smoke, they may automatically assume there to be a fire and react to evacuate. The source of the smoke may be from some other non-hazardous source, yet the perceived risk of fire, without adequate information, may invoke a panic response if information about the source of the smoke is not provided.


These involve the load capacities of the public spaces within a temporary or permanent venue including dance floors, doorways, ingress and exit routes. It is the space or floor area that will host a crowd. It is usually measured in m²/person. Factors that can affect the amount of space include:

  • Venue Capacity - The total capacity of each part of the venue will be derived by fire engineering standards and the 2010 Building Code of Australia (for permanent venue structures).
  • Configuration - Layout and configuration of temporary structures within available space.
  • Traffic Flow - The anticipated flow patterns on ingress / egress and crowd milling areas throughout the event.
  • Maximum Occupancies - Maximum occupancies on stairs, ramps and escalators at any one time.


This is the period of exposure to excessive crowd densities. This can be demonstrated where a crush is experienced along egress routes during mass egress from the venue at the end of an event. The venue can reduce the periods of intense crowd densities through staggering post event entertainment for egress and staggering public transport arrival times on ingress.

FIST Model Application

The application of the FIST Principle as a causal model for crowd crush is potentially useful for venue operators and event organisers when developing proactive strategies to address the four elements of the model during event risk management planning.

This model can be used for the management of any public space. While the worst case scenario is a fatality resulting from crowd crush, the more foreseeable scenario is that your event patrons have an unpleasant experience while getting shoved around in a crowd. Such unpleasant customer experiences can attract bad press and reputational damage to the event or host venue.