Sweden. The Soviet Red Army captured the city on 26April 1945. While the majority of the almost 400,000 inhabitants had left the city, between 6,000 and 20,000 inhabitants remained in late April. On 28 April 1945 Polish authorities tried to gain control, but in the following month, the Polish administration was twice forced to leave. Finally the permanent handover occurred on 5July 1945. In the meantime, part of the German population had returned, believing it might become part of the Soviet occupation zone of Germany. The Soviet authorities had already appointed the German Communists Erich Spiegel and Erich Wiesner as mayors. Stettin is located mostly west of the Oder river, which was expected to become Poland's new western border, placing Stettin in East Germany. This would have been in accordance with the Potsdam Agreement between the victorious Allied Powers, which envisaged the new border to be in "a line running from the Baltic Sea immediately west of Swinemünde, and thence along the Oder River[...]". Because of the returnees, the German population of the town swelled to 84,000. The mortality rate was at 20%, primarily due to starvation. However, Stettin and the mouth of the Oder River became Polish on 5July 1945, as had been decided in a treaty signed on 26July 1944 between the Soviet Union and the Soviet-controlled Polish Committee of National Liberation (PKWN) (also known as "the Lublin Poles", as contrasted with the London-based Polish government-in-exile). On 4October 1945, the decisive land border of Poland was established west of the 1945 line, and the city was renamed to its historic Polish name Szczecin, but the area excluded the Police area, the Oder river itself, and the port of Szczecin, which remained under Soviet administration. The Oder river was handed over to Polish administration in September 1946, followed by the port between February 1946 and May 1954. Post-war While in 1945 the number of pre-war inhabitants dropped to 57,215 on 31 October 1945, the systematic expulsion of Germans started on 22 February 1946 and continued until late 1947, in accordance with the Potsdam Agreement. In December 1946 about 17,000 German inhabitants remained, while the number of Poles living in the city reached 100,000. To ease the tensions between settlers from different regions, and help overcome fear caused by the continued presence of the Soviet troops, a special event was organised in April 1946 with 50,000 visitors in the partly