In a final attempt for victory, Hitler concentrated his best SS troops in the Ardennes Forest south of Monshau under strict secrecy, planning airborne drops, a massive armored assault, and Special Forces attacks by SS troops using American uniforms and equipment to penetrate U.S. lines while bad weather shielded the operation from Allied air attack. The German counteroffensive began on December 16th, aiming to cut through to Antwerp, and drove a significant salient into Allied lines as confusion spread among Allied commanders; Eisenhower recognized the scale of the attack and began moving armored divisions to stop it. Although the German airdrop was not militarily effective, it sent psychological shock waves across the Allied front, and on December 17th Eisenhower committed his theater reserve, the 101st Airborne Division, to hold vital road centers at Bastogne, where it was quickly surrounded. When the German commander demanded surrender, Brig. Gen. A. C. McAuliffe replied with a single word, "NUTS!" On December 18th Bradley ordered Patton to suspend the Saar offensive and move north, and Patton began his drive to relieve Bastogne on December 22nd, though intercepted U.S. radio messages and German readiness slowed his progress. Clearing weather on December 23rd allowed aerial resupply of Bastogne, while German advances were also slowing because of fuel shortages and traffic jams. On December 26th the U.S. 2nd Armored Division crushed the 2nd Panzer Division, and Patton broke through to relieve the 101st at Bastogne. Between December 16th and January 3rd, the U.S. suffered 41,315 casualties. By January 3rd, 1945, the German salient had reached its height, and U.S. forces began retaking lost ground against Germans who, under Hitler's standing order forbidding voluntary withdrawal, fought a hard retreat shaped by winter warfare experience from the Russian front. The Allies fought through January 1945 to restore the front to its December 16th, 1944 position, and from January 3, 1945 to March 28, 1945 the U.S. suffered another 39,672 casualties. The struggle became the largest battle in U.S. history and marked the moment to turn the tables on Germany.