The year 2018 will mark the 100th anniversary of the deadliest influenza outbreak in history. Scientists estimate that the influenza pandemic of 1918 killed more than 50 million people around the world. Other estimates go much higher. Because of a lack of medical record-keeping, we may never know the exact number. However, the outbreak was a global disaster, killing more people than World War I. In the United States, historians at the National Archives state that the flu afflicted over 25 percent of the U.S. population. In one year, the average life expectancy in the United States dropped by 12 years. It was a fast killer. Again, archival records state that some victims died within hours of their first symptoms. Others died after a few days. Their lungs filled with fluid and they suffocated to death.