Behind wall at border Stresemann and Kothener Strasse East German soldiers erecting tetrahedrons tank barriers made of streetcar tracks in Berlin Nov. 20, 1961. Background three American soldiers looking over the wall into West Berlin. (AP Photo/ Kreusch) Behind wall at border Stresemann and Kothener Strasse East German soldiers erecting tetrahedrons tank barriers made of streetcar tracks in Berlin Nov. 20, 1961. Background three American soldiers looking over the wall into West Berlin. (AP Photo/ Kreusch)
