A catastrophic disaster is defined as an event that results in extraordinary levels of mass casualties, damage, or disruption, severely affecting the population, infrastructure, and government functions. The severity of such an event overwhelms the capabilities of local, state, and even traditional federal response mechanisms. Consequently, it requires a massive, unified national response that includes substantial assistance from the Department of Defense (military) for logistics, search and rescue, security, and other critical life-sustaining missions, as outlined in national response protocols.

A. Minor disaster: This is handled effectively at the local level using local resources, without the need for state or federal intervention.

B. Medium disaster: This may overwhelm local capabilities, requiring regional mutual aid or limited state assistance, but not substantial federal or military support.

C. Major disaster: This is a formal presidential declaration under the Stafford Act that triggers significant federal assistance, but it does not automatically imply the scale of devastation requiring military involvement.

1. FEMA. (2019). National Response Framework (4th ed.). The glossary defines a "Catastrophic Incident" as an event resulting in "extraordinary levels of mass casualties, damage, or disruption" that requires a response far exceeding routine federal assistance. The Catastrophic Incident Annex (p. 73) specifically details the framework for mobilizing all national resources, including significant Department of Defense support.

2. National Fire Protection Association. (2019). NFPA 1600: Standard on Continuity, Emergency, and Crisis Management. Annex A, Section A.5.5.2 discusses the scaling of incidents. A Type 1 incident, the most complex classification, involves national-level resources and aligns with the operational requirements of a catastrophic disaster, often necessitating federal and military assets.

3. Cote, A. E. (Ed.). (2008). Fire Protection Handbook (20th ed.). National Fire Protection Association. Section 12, Chapter 2, "Emergency Management," describes the tiered response system. It clarifies that catastrophic events exhaust state and federal civilian agency resources, making the integration of military assets essential for an effective response (pp. 12-20 to 12-22).