The Battle of Franklin was so costly that in five hours it produced more American casualties than were lost in the first twenty-four hours of the Invasion of Normandy on June 6, 1944, the largest amphibious assault in history. In both battles, there is still no final casualty count because both were part of massive continuing campaigns. At Franklin and in France, many officers responsible for tracking losses were themselves killed in combat, records were damaged or misplaced, and reports were often incomplete, so the exact number who fell on either side may never be known. Most of those listed as missing at Franklin were actually prisoners of war, and at the time there was no formal requirement to provide the names and numbers of captured opponents. During World War II, the Geneva Convention of 1929 required each side to report all prisoners in its possession. On D-Day, few Americans were captured, and many of the missing had drowned off the beaches of Normandy. In both battles, artillery and other weapons often destroyed bodies beyond any hope of identification. American soldiers who landed on Omaha Beach and Utah Beach on June 6, 1944, faced long- and short-range artillery, automatic rifles, hand grenades, land mines, and machine guns, yet they suffered a lower percentage of casualties than those who fought at the Battle of Franklin.