flu that spread over a large area in 1918
1918 flu pandemic The 1918 flu pandemic (January 1918 – December 1920) was an unusually deadly influenza pandemic, the first of the two pandemics involving H1N1 influenza virus.[1] It infected 500 million people around the world,[2] including people on remote Pacific islands and in the Arctic, and resulted in the deaths of 50 to 100 million (three to five percent of the world's population),[3] making it one of the deadliest natural disasters in human history.[4][5][6]
World War I casualties The total number of deaths includes from 9 to 11 million military personnel and about 5 to 6 million civilians. The Triple Entente (also known as the Allies) lost about 6 million military personnel while the Central Powers lost about 4 million. At least 2 million died from diseases and 6 million went missing, presumed dead. This article lists the casualties of the belligerent powers based on official published sources. About two-thirds of military deaths in World War I were in battle, unlike the conflicts that took place in the 19th century when the majority of deaths were due to disease. Nevertheless, disease, including the 1918 flu pandemic and deaths while held as prisoners of war, still caused about one third of total military deaths for all belligerents.