On Tuesday, up to a dozen tornadoes ripped through the Dallas, Texas area, injuring 17 people, damaging 650 homes and another 300 structures, and throwing 7-ton tractor-trailers around like toys. At the international airport, more than 100 planes were damaged, grounding 500 flights on Wednesday. Thousands were left without power (Reuters, April 4, 2012; USA Today, April 4, 2012). 2012 has already seen about double the number of tornadoes of a typical year in this country.