U.S. tropical cyclones, including hurricanes, indirectly cause thousands of deaths for nearly 15 years after a storm. Researchers estimate an average U.S. tropical cyclone indirectly causes 7,000 to 11,000 excess deaths. All told, they estimate tropical storms since 1930 have contributed to between 3.6 million and 5.2 million deaths in the U.S. -- more than all deaths nationwide from motor vehicle accidents, infectious diseases, or battle deaths in wars during the same period.