The 1918 flu pandemic (the "Spanish flu") was an influenza pandemic. It was an unusually severe and deadly pandemic that spread across the world. Historical and epidemiological data are inadequate to identify the geographic origin. Most victims were healthy young adults. The pandemic lasted from January 1918 to December 1920, spreading even to the Arctic and remote Pacific islands. Between 50 and 130 million died, making it one of the deadliest natural disasters in human history!