"Mass fatality incidents, although rare, pose unique challenges to local and state disaster management and response agencies. This guide was developed by the FBI Office for Victim Assistance and the NTSB [National Transportation Safety Board] Transportation Disaster Assistance Division for local and state agencies involved in the response to mass fatality events. It provides an overview of the components of the family assistance process and family assistance center operations as they relate to transportation and criminal incidents. The Family Assistance Center (FAC) model is a framework for providing family assistance following a mass fatality incident (MFI). Family assistance is defined as the provision of services and information to the family members of those killed and to those injured or otherwise impacted by the incident. Although the specific needs of those impacted by a MFI will vary widely, family assistance presumes that the provision of information and access to services is essential."