evidence: influenza pandemic of 1918–19 [...] influenza pandemic of 1918–19, the most severe influenza outbreak of the 20th century and, in terms of total numbers of deaths, among the most devastating pandemics in human history. [...] Outbreaks of the flu occurred in nearly every inhabited part of the world, first in ports, then spreading from city to city along the main transportation routes. India is believed to have suffered at least 12.5 million deaths during the pandemic, and the disease reached distant islands in the South Pacific, including New Zealand and Samoa. In the United States about 550,000 people died. Most deaths worldwide occurred during the brutal second and third waves. Other outbreaks of Spanish influenza occurred in the 1920s but with declining virulence.