On 18 December 1944, the 37th got its march order—to move north against the German penetration, which was causing alarm to the Allied High Command. On the same day, the 101st Airborne Division was moved by truck to establish a strongpoint at the key road and rail junction of Bastogne, in Belgium. By the time the 37th arrived at the south flank of the German penetration, the 101st Airborne was cut off on all sides by the enemy drive. The 37th became the spearhead of the 4th Armored Division's drive to relieve the paratroopers in Bastogne. The 37th moved out in a feathery snowfall at 0600 hours on 22 December 1944, attacking northward against German airborne troops. The 37th Tank Battalion and the 53rd Armored Infantry Battalion made up the 4th Armored Division's Combat Command-B (CCB). In a bloody engagement against German paratroopers wearing American uniforms, CCB took Bigonville.