Why Spanish Flu Killed Over 50 Million People - Deadliest Plague in Modern History

The Spanish flu swept the world between January 1918 through December 1920, infecting over 500 million people around the world. At first, it was just a normal flu, but it's second wave was the deadliest. But just why did the Spanish flu decimate the world population and what made it so deadly? In todays animated history video, we're taking a look at the lessons we can learn from Spanish flu and see just what went wrong.