On 3 September 1943, Italy surrendered to the Allied powers. Hoping to occupy as much of the country as humanly possible before the German Army could react, the U.S. Fifth Army prepared to attack Salerno. On 10 September, elements of the division conducted its second landing at Agropoli and Paestum with the 36th Infantry Division, on the southernmost beaches of the attack. Opposing them were elements of the German 29th Panzergrenadier Division and XVI Panzer Corps. Against stiff resistance, the 45th pushed to the Calore River after a week of heavy fighting. The Fifth Army was battered and pushed back by German forces until 20 September, when Allied forces were finally able to break out and establish a more secure beachhead.