World War I casualties
The total number of military and civilian casualties in World War I were about 40 million: estimates range from 15 to 19 million deaths and about 23 million wounded military personnel, ranking it among the deadliest conflicts in human history.
Home front during World War I
About 10 million combatants and seven million civilians died during the entire war, including many weakened by years of malnutrition; they fell in the worldwide Spanish Flu pandemic, which struck late in 1918, just as the war was ending.