 Complete the following phrase:  Hitler retreated to his Führerbunker in Berlin on 16 January 1945. It was clear to the Nazi leadership that the battle for Berlin would be the final battle of the war in Europe. Some 325,000 soldiers of Germanys Army Group B were surrounded and captured in the Ruhr Pocket on 18 April, leaving the path open for U.S. forces to reach Berlin. By 11 April the Americans crossed the Elbe, to the west of the city. On 16 April, Soviet forces to the east crossed the Oder and commenced the battle for the 