Virtual Reenactment of the Itaewon Crowd Crush Using Kinodynamic Simulation

We propose new crowd simulation methods to virtually reenact the Itaewon disaster that occurred in 2022 due to the extreme crowd density. Conventional techniques make it challenging to simulate diverse, extremely dense crowd behaviors such as crowd surge, fluidization, and falls observed at the Itaewon disaster. This paper proposes a kinodynamic agent simulation combining kinematic agents for low-density crowds, hydrodynamic and hydrostatic agents for high-density crowds, and articulated passive agents for high-density crowds in dense contact. In order to perform co-simulation among heterogeneous agent types, we use a message-passing mechanism to share relevant kinematic and dynamic information among agents and make agent-type transitions based on crowd density and contact forces. Experiments show that the proposed hybrid simulation approach can accurately reenact crowd phenomena observed at the Itaewon compared to the CCTV footage. Moreover, our ablation study supports the use of kinodynamic agents to faithfully reconstruct the Itaewon crowd behavior. Furthermore, we run three what-if scenarios to explore the possibilities of using our techniques to help prevent incidents in the future. Finally, to demonstrate the applicability of our proposed methods to other types of extreme crowd behaviors besides the Itaewon disaster, we simulate two other real-world crowd incidents using our techniques.