The first case of Spanish Influenza is diagnosed on this day. Private Albert Gitchell, a company cook at Fort Riley, Kansas is preparing to ship out to Europe when he comes down with what appears to be a severe cold. He's isolated in the infirmary, but within hours many more soldiers at Fort Riley report similar symptoms.
This is the start of the great influenza pandemic which will kill more people than World War I. It will be the most deadly epidemic in known history, killing more people in a single year than in the worst four years of the Black Death.