1918. World War I was still raging. Then another threat emerged. The Spanish Flu pandemic spread across the globe with devastating speed. In just two years, it infected approximately 500 million people—one-third of the world's population at that time. An estimated 50 million people died, though some historians believe the number reached 100 million. Unlike typical influenza, this strain killed healthy young adults in their prime. Hospitals were completely overwhelmed. Entire communities lost doz