Civilian casualty ratio
Some 7 million combatants on both sides are estimated to have died during World War I, along with an estimated 10 million non-combatants, including 6.6 million civilians. The civilian casualty ratio in this estimate would be about 59%. Boris Urlanis notes a lack of data on civilian losses in the Ottoman Empire, but estimates 8.6 million military killed and dead and 6 million civilians killed and dead in the other warring countries. The civilian casualty ratio in this estimate would be about 42%. Most of the civilian fatalities were due to famine, typhus, or Spanish flu rather than combat action. The relatively low ratio of civilian casualties in this war is due to the fact that the front lines on the main battlefront, the Western Front, were static for most of the war, so that civilians were able to avoid the combat zones.
World War I
The Battle of the Somme was an Anglo-French offensive of July to November 1916. The opening day of the offensive (1 July 1916) was the bloodiest day in the history of the British Army, suffering 57,470 casualties, including 19,240 dead. The entire Somme offensive cost the British Army some 420,000 casualties. The French suffered another estimated 200,000 casualties and the Germans an estimated 500,000. Gun fire wasn't the only factor taking lives; the diseases that emerged in the trenches were a major killer on both sides. The living conditions made it so that countless diseases and infections occurred, such as trench foot, shell shock, blindness/burns from mustard gas, lice, trench fever, cooties (body lice) and the ‘Spanish Flu’.