Cases involving either slow-moving thunderstorms or a series of storms which move repeatedly across the same area (sometimes called train-echo storms) frequently result in flash flooding. The total number of flash flood deaths has exceeded tornado fatalities during the last several decades.
Photograph by: NWS
Two factors seem to be responsible for this: public apathy regarding the flash flood threat and increased urbanization. When concrete replaces soil, rain water will run off rather than soak in. Flash flood producing rainfall has made this type of dramatic rescue attempt (pictured above) all too familiar, especially in urban areas and popular mountain camping spots.
Another danger associated with thunderstorms, especially to personal property, is hail. This hailfall occurred in Altus, Oklahoma in 1982 and was accompanied by several tornadoes. Hail causes more monetary loss than any other type of thunderstorm-spawned severe weather.
Photograph by: NSSL
Annually, the United States alone suffers about one billion dollars in crop damage from hail. Hail rarely kills people, but these were hollow words in China in May, 1986 when 100 people were killed, 9,000 injured, and 35,000 homes destroyed by an intense hailstorm.