1935 Florida Keys Labor Day Hurricane
This Category 5 storm, considered the strongest to hit the U.S. in the 20th century, brought 200-mph (320-kph) winds and soaking rain to the upper and middle Florida Keys and killed approximately 400 people. More than half of the dead were World War I veterans who had been working on building a highway from Key West to Key Largo. Damage in the United States was estimated at $6 million [sources: USA Today, National Weather Service].
This storm is simply known as the "Labor Day Hurricane" because the practice of naming hurricanes didn't begin until 1953. (And the World Meteorological Organization gave storms only female handles until 1978.) The storm also struck well before advances in weather tracking technology, including the regular use of Doppler radar, that predict where a storm might end up, leaving residents largely in the dark as the hurricane approached. Many of the victims had waited anxiously for an evacuation train that never came – it was washed away from the tracks [sources: National Weather Service, USA Today, National Weather Service].