This workshop addressed the preparation, response, and recovery from a catastrophic event. An event may be considered catastrophic when the number of people affected is greater than that normally covered by a typical federal response area and the time to recover was well beyond that of a localized disaster. Also, catastrophic events involve almost complete disruption of communications and other critical infrastructure (such as the electrical power grid). A spectrum chart (Figure 1) helps to illustrate the factors and scope of emergency events that may require the response of organizations at the local, state, and federal levels. The vertical axis of the diagram represents the number of people affected and the horizontal axis represents the time to recover from a given event. Some examples are weather events (such as floods and hurricanes); geological events (such as earthquakes or tsunamis); and biological events (such as an influenza outbreak).