Building design and its effect on evacuation efficiency and casualty levels during an indoor active shooter incident

The continuous increase in the frequency of active shooter incidents demands the implementation of strategies that can help reduce the lethal effects of these tragedies. Providing victims with a building environment that facilitates a safe and efficient evacuation can be an effective strategy, with several expected benefits for the reduction of levels of injuries and casualties. This study performed a systematic evaluation of three important building design parameters-building exit width, door width, and hall width-to determine their potential effects on the reduction of casualties and efficiency of evacuation. Given the infeasibility of performing real-life drills for active shooter incidents, this study used computer simulation, specifically agent-based modeling (ABM), to perform the proposed evaluation. The social forces model of pedestrian dynamics was used as the model of pedestrian motion. A school-like building setting was modeled in the simulation tool, and the above-mentioned parameters were tested using 150 different simulation scenarios at different levels of building occupancy. The results showed that hall width and door width are the parameters with the largest observed benefits for the improved safety of victims. Additionally, important insights about the inter-dependency between some of the parameters were obtained. The results from this study provide a base of analytic evidence that is expected to open the discussion about the importance of considering this type of emergency when designing facilities.