It was born in a tropical breeze over the southern Caribbean Sea. By the time it drew its last breath in the Bahamas 13 days later, it had destroyed crops in three countries, wrecked five billion U.S. dollars’ worth of buildings, bridges and roads, left 3 million homeless, and killed 11,000—making a 1998 storm named Mitch the deadliest Atlantic Ocean hurricane since 1780.

Cyclones, typhoons, and willy-willies are names that are applied in different parts of the world to the same creatures: violent tropical ocean storms with winds spiraling around their chimney-like centers at speeds that can top 155 miles (250 kilometers) an hour.

Mariners fear those driving winds and the monster waves they produce. But hurricanes bring an even richer variety of terrors to those caught on land. Storm surge—the buildup of water at a storm’s center—can drown a coastline. Torrential rains may threaten communities hundreds of miles away from the point of landfall.

During the past 30 years more U.S. hurricane deaths have resulted from rain-induced inland flooding than from storm surge. Hurricane Floyd in 1999 dumped rain on hundreds of miles of the east coast, resulting in an estimated 6 billion dollars in flood damages. All but 6 of 56 deaths were caused by flooding far from the point of impact. Thirteen states, ranging from Florida to Maine, were declared major disaster areas, with nearly 3 million people fleeing their homes in the largest peacetime evacuation in U.S. history.