The 1918 flu pandemic (the Spanish Flu) was an influenza pandemic that spread widely across the world.  The pandemic lasted from March 1918 to June 1920, spreading even to the Arctic and remote Pacific islands. Between 50 and 100 million died, making it one of the deadliest natural disasters in human history. An estimated 50 million people, about 3% of the world's population (1.6 billion at the time), died of the disease. 500 million, or 1/3 were infected. This disease killed some 650,000 people in the United States in 1918-1919.