Through the Army was reluctant to send Black units into combat, famous segregated units, such as the Tuskegee Airmen and the U.S. 761st Tank Battalion proved their value in combat.[160] Approximately 75 percent of the soldiers who served in the European theater as truckers for the Red Ball Express and kept Allied supply lines open were African-American.[161] During the crisis of the Battle of the Bulge in December 1944, the Army allowed several integrated infantry platoons to be formed, through these were broken up once the crisis passed.[3] However, the experiment of the integrated platoons in December 1944 showed that integration did not mean the collapse of military discipline as many claimed that it would, and was a factor in the later desegregation of the armed forces.[157] A total of 708 African Americans were killed in combat during World War II.[162]