By the time the storms were finished three and a half hours later, 689 people lay dead or dying along a 219-mile (352 kilometers) trail of destruction across Missouri, Illinois, and Indiana. The Tri-State Tornado Outbreak of 1925 was especially treacherous because many of the twisters came in so low that they couldnt be seen at a distance.
An average of 800 tornadoes are reported in the United States every year, every one a potential killer. Many occur in Tornado Alley, the central Plains from Texas to Nebraska. But they can happen anytime, anyplaceeven on the side of a mountain. An outbreak in May 1999 that swept from Texas to the northern Plains was one of the costliest in U.S. history, with an estimated $1 billion dollars in damages. On May 3, in the Oklahoma City suburbs alone, 36 people were killed and more than 300 were injured.
Flying debris and winds potentially more violent than a hurricane create most of the havoc. At their worst, tornadoes can rip apart ordinary houses, toss cars into the air, and turn small objects into bullets. Waterspoutsweaker marine cousins that form over warm wateralso can be hazardous to human health.