| Type of Event | Examples |
|---|---|
| Natural | Flood, earthquake, hurricane, tornado, typhoon, landslide, tsunami, ice storm, drought, wildfire, epidemic, disease |
| Accidental | Chemical spill, transportation accident, industrial accident, radiological incident, nuclear incident, explosion, utility outage |
| Civil/Political | Public demonstration, protest, civil disturbance, strike, mass immigration |
| Terrorist/Criminal | Chemical attack, biological attack, radiological attack, nuclear attack, high-explosive attack, war |
| Other | Inauguration, State of the Union, Olympics, major sporting event, summit conference, cyber attack |