Fort Driant lay in Maj. Gen. Walton H. Walker's XX Corps sector. Walker gave the mission of taking the fort to Maj. Gen. S. LeRoy Irwin's 5th Infantry Division. On 27 September, Irwin launched the 2d Battalion of the 11th Infantry, supported by a company from the 818th Tank Destroyer Battalion, against the fort. The attack failed in the face of determined opposition. On 3 October, Irwin tried again, once more sending the 2d Battalion, 11th Infantry, against the fort. This time, the unit--reinforced by a rifle company from its regiment's 1st Battalion, twelve medium tanks from the 735th Tank Battalion, and a company of combat engineers--breached the defenses of the fort, but with heavy losses. Irwin quickly began feeding in companies and battalions from the 2d and 10th Infantry regiments in an attempt to overwhelm the Germans.
The fighting within Driant now became a melee. In the maze of underground passageways that crisscrossed the fort, American and German soldiers fought what became known as "the battle of the tunnels." By 9 October, the struggle had cost over 500 American casualties, yet the Germans still seemed capable of holding the fort. Finally, on 9 October, the Third Army ordered the attack halted and during the night of 12-13 October the last American soldiers slipped away.
After the failure at Fort Driant, the Third Army paused and marshaled its strength. Although the 90th Division had fought a tough battle to capture Maizieres-les-Metz, six miles north of Metz, the Third Army's operations in the latter half of October centered mainly on "aggressive patrolling," while absorbing supplies and replacements for future efforts.
October proved a difficult month as well for Devers' 6th Army Group. Although Patch's Seventh Army seized the high ground in the St. Die area, supply shortages and increasingly harsh weather conspired to slow the advance as Devers' forces pushed deeper into the heavily wooded Vosges Mountains. Likewise, the First French Army had to abandon its advance toward Colmar and Belfort in the face of poor weather, limited supplies, and mountainous terrain that compartmentalized the battlefield.
Page 8 (The Rhineland)