FILE - In this Aug 13, 1961 b/w file picture members of the East German military remove paving blocks on Friedrich Strasse in East Berlin August 13, 1961 as East Germany tightened the border crossing, between East and West Berlin. AP Photographer Peter Hillebrecht was on assignment in Berlin as the construction of the Berlin Wall starts on Aug. 13, 1961 and he was one of the first photographers to cover this historic event. When the wall was first built, nobody knew what was going to happen next. Many people were afraid that the wall would serve as a provocation and turn to the Cold War into a hot one.(AP Photo)