much of the planning of the 1936 Berlin Summer Olympic Games took place. World War II As was the case in most of central Berlin, almost all of the buildings around Potsdamer Platz were turned to rubble by air raids and heavy artillery bombardment during the last years of World War II. The three most destructive raids (out of 363 that the city suffered), occurred on 23 November 1943, and 3 and 26 February 1945. Things were not helped by the very close proximity of Hitler's Reich Chancellery, just one block away in Voßstraße, and many other Nazi government edifices nearby as well, and so Potsdamer Platz was right in a major target area. Once the bombing and shelling had largely ceased, the ground invasion began as Soviet forces stormed the centre of Berlin street by street, building by building, aiming to capture the Reich Chancellery and other key symbols of the Nazi government. When the city was divided into sectors by the occupying Allies at the end of the war, the square found itself on the boundary between the American, British and Soviet sectors. Despite all the devastation, commercial life reappeared in the ruins around Potsdamer Platz within just a few weeks of war's end. The lower floors of a few buildings were patched up enough to allow business of a sort to resume. The U-Bahn and S-Bahn were partially operational again from 2 June 1946, fully from 16 November 1947 (although repairs were not completed until May 1948) and trams by 1952. Part of the Haus Vaterland reopened in 1948 in a much simplified form. The new East German state-owned retail business H.O. (Handelsorganisation, meaning Trading Organisation), had seized almost all of Wertheim's former assets in the newly created German Democratic Republic but, unable to start up the giant Leipziger Platz store again (it was too badly damaged), it opened a new Kaufhaus (department store) on the ground floor of Columbushaus. An office of the Kasernierte Volkspolizei (literally "Barracked People's Police") – the military precursor of the Nationale Volksarmee (National People's Army), occupied the floor above. Meanwhile, a row of new single-storey shops was erected along Potsdamer Straße. Out on the streets, even the flower-sellers, for whom the area had once been renowned, were doing brisk business again. The area around Potsdamer Platz had also become a focus for black market trading. Since the American, British and Soviet