Southwest Florida is vulnerable to a variety of natural and technological hazards and sociological-based threats. The natural hazards include excessive rainfall, storm surge flooding, destructive winds and lightning normally cause by severe thunderstorms, hurricanes and tornadoes. Droughts and freezes impact the region's agricultural economy; wildfires impact natural resources and rural development. Dike failures have occurred from heavy rainfall and could occur from hurricane wind driven water surges. Technological hazards are hazardous material incidents creating spills and plumes, hazardous waste sites and mass care and casualty events such as are possible from airplane crashes, nuclear accidents, civil disorder, and spontaneous mass immigration. (The latter two are considered sociological caused threats.)