If we examine the underlying causality in worldwide accidents we observe that there are some fundamental (root/distal) causes. In all cases accidents/incidents don't just happen - there is always a cause.
Brief history of crowd disasters
Over the last 20 years there have been a number of significant crowd related disasters. Below is a short list (but not all). We reviewed the underlying causality in these disasters to understand how the DIM-ICE model can be adapted to improve understanding of causality in accident/incidents and how we can develop better teaching programme to try and prevent future accidents that have similar underlying causes.
As we can see from the above there is a high percentage of design related disasters (too many people, not enough space). One of the key elements of crowd modelling is to understand the capacity of the space, how quickly it will fill and what time it will take to reach critical density.
Risk is Dynamic
Risk change over time. Crowd risks can be dependent on a number of factors and on a number of external influences. So understand how risks change with time is fundamental to the development of a robust crowd management plan.