Each year in the U.S., more people are killed by tornadoes than by earthquakes and hurricanes combined. But the chances of one particular structure being hit by a tornado are so remote that no national codes address the often-deadly storms. Of late, the fickle twisters are shifting northward, invading—and often leveling—more densely populated areas. In response, communities, engineers, researchers and others are rallying defenses as never before to minimize twister-triggered death and destruction.
One of those communities is Moore, Okla. Last year on May 22, the city was hit by an Enhanced Fujita Scale 5 (EF-5) tornado—the strongest storm rating. The twister slammed into two schools, killing 10 children.