A naturally occurring calamitous event bringing great damage, loss, or destruction such as tornadoes, hurricanes, widespread flooding, wildland fires, earthquakes, and related occurrences.
Minister of Aboriginal Affairs and Northern Development, Aboriginal Affairs and Northern Development Canada (AANDC) National Emergency Management Plan, Glossary, Minister of Public Works and Government Services, Ottawa, Canada 2011. http://www.aadnc-aandc.gc.ca/eng/1324572607784#a1, (ND/ Avalan/ Snowpack - Amer) {133}