Recent catastrophic events have brought into focus the importance of planning for the evacuation needs of all persons, regardless of their diverse physical and mental abilities. While these efforts are primarily concerned with the activities before and after a crisis, there is also a renewed interest in evaluating how effectively the built environment accommodates the needs of all individuals during a crisis. This discussion focuses on the current body of knowledge concerning the relationship between the design of the built environment, the collective egress behavior of complex decentralized groups of individuals, and the ability of individuals with disabilities to effectively egress from the built environment during emergency events.