September 22, 2021
This photo made available by the Library of Congress shows a demonstration at the Red Cross Emergency Ambulance Station in Washington during the influenza pandemic of 1918. Historians think the pandemic started in the U.S. in Kansas in early 1918, and by winter 1919 the virus had infected a third of the global population and killed at least 50 million people, including 675,000 Americans. Some estimates put the toll as high as 100 million. (Library of Congress via AP, File)