What would cause a tornado disaster?

Tornadoes are usually accompanied by strong winds, heavy showers, hail, lightning and other phenomena, by passing through along the tornado path, common trees were uprooted, people, vehicles, livestock will be rolled up, the structure of the poor will be the destruction of buildings and caused by power outage or gas pipeline rupture caused by fire or explosion, etc., so be very severe casualties and losses. Taiwan due to weather and terrain constraints, the smaller tornadoes, relatively minor damage, but tornadoes may occur in the region, remain on guard.