Mass casualty incident
A mass casualty situation is one in which the number of victims exceeds the capacity of available emergency services. It is differentiated from a multiple casualty incident, where there are a large number of victims, but that are within the capacity of the local resources, perhaps with the need to extend working hours, bring in off-duty personnel, etc. Both are situations where triage is required. In a mass casualty situation, the triage process is likely to assign some victims to "expectant" or "moribund" categories, where only comfort measures will be provided to those conscious victims in the category, in which all are expected to die. Only life-preserving surgery will be done.
Increasingly, the civilian paradigm for managing such situations is the Hospital Emergency Incident Command System, which is more derived from the Incident Command System than the National Incident Management System. 
Another is the Hospital Emergency Response Training (HERT), which partially based, for legal reasons, on the National Incident Management System rather than the Incident Command System. It also differs from HEICS in that it includes field response by hospital-level personnel, not hospital care or emergency medical system care alone. While it is not a full hazardous materials (HAZMAT) or weapons of mass destruction response system, it addresses aspects of those issues. 
- NIMS Integration Center, Federal Emergency Management Agency, U.S. Department of Homeland Security (May 13, 2005), NIMS and the Hospital Emergency Incident Command System
- Noble (Alabama) Training Center, U.S. Department of Homeland Security, Hospital Emergency Response Training (HERT) for Mass Casualty Incidents (MCI) Train-the-Trainer Course