positions. Major General Terry de la Mesa Allen Sr.—commanding the U.S. 1st Infantry Division—was threatened when two tanks came near his headquarters, but he shrugged off suggestions of moving, "I will like hell pull out, and I'll shoot the first bastard who does." The German attack lost momentum when it ran into a minefield. When the Germans slowed to reorganise, U.S. artillery and anti-tank guns engaged, including 31 M10 tank destroyers which had recently arrived. Over the next hour, 30 of the 10th Panzer's tanks were destroyed, and by 09:00 they retreated from the valley. A second attempt was made at 16:45, after waiting for the infantry to form up. Once again the U.S. artillery was able to disrupt the attack, eventually breaking the charge and inflicting heavy losses. Realizing that further attacks were hopeless, the rest of the 10th Panzer Division dug in on hills to the east or retreated back to the German headquarters at Gabès. Allied attacks On 19 March, the British 8th Army launched their attack on the Mareth Line, at first with little success. Over the next week, the U.S. forces slowly moved forward to take the rest of the interior plains and set up lines across the entire Eastern Dorsals. The German and Italian defenses and reserves were heavy, and the progress was both slow and costly. On 23 March, the 10th Panzer Division attacked Lieutenant-Colonel Robert H. York's 1st Battalion, 18th Infantry Regiment, 1st Infantry Division, and the German tanks broke through the valley between the 3rd and 1st Battalions of the 1st Division, reaching a position about six miles to the rear of the 1st Battalion. In the action, the German tanks and self-propelled guns along with German troops riding in carriers and trucks overran the 32nd Field Artillery Battalion and part of the 5th Field Artillery Battalion, and the Italian High Command reported that 40 tanks had been destroyed and 170 Allied troops had been captured in "central and southern Tunisia". On 26 March, in Operation Supercharge II, a British force sent via an outflanking inland route attacked the Tebaga Gap to the north of the Mareth line, and their breakthrough left the Mareth defenses untenable. The Axis forces retreated about 40 miles to a new line set up at Wadi Akarit, north of Gabès at . This made the U.S. position even more valuable, since the road through El Guettar