World War I casualties
The total number of deaths includes from 9 to 11 million military personnel. The civilian death toll was about 8 million, including about 6 million due to war-related famine and disease. 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.
Atlantic U-boat campaign of World War I
Of the 12.5 million tons of Allied shipping destroyed in World War I, over 8 million tons, two thirds of the total, had been sunk in the waters of the Atlantic war zone. Of the 178 U-boats destroyed during the war, 153 had been from the Atlantic forces, 77 from the much larger High Seas Flotillas and 76 from the much smaller Flanders force.