Two days after the Germans launched their Ardennes Offensive, the 4th AD entered the fight (18 December 1944), racing northwest into Belgium, covering 150 miles in 19 hours. The 4th AD, spearheading Patton's Third Army, attacked the Germans at Bastogne and, on 26 December, was the first unit (Company C, 37th Tank Battalion led the 4th Armored Division column that relieved Bastogne during the Battle of the Bulge) to break through at Bastogne and relieve the besieged 101st Airborne Division. Six weeks later the 4th AD jumped off from Luxembourg City in an eastward plunge that carried it across the Moselle River at Trier, south, and east to Worms, and across the Rhine, 24–25 March 1945. Advancing all night, the 4th AD crossed the Main River the next day, south of Hanau, and continued to push on. Lauterbach fell 29 March, Creuzburg across the Werra on 1 April, Gotha on 4 April – where the 4th AD liberated Ohrdruf concentration camp, the first Nazi camp liberated by U.S. troops. By 12 April the 4th AD was across the Saale River. Pursuit of the enemy continued, and by 6 May the division had crossed into Czechoslovakia and established a bridgehead across the Otava River at Strakonice, with forwarding elements at Pisek. The 4th AD was reassigned to the XII Corps on 30 April 1945. The 4th AD received the following Letter of Commendation: