Due to the mass migration of East German citizens to the FDR, in the night from the 12th to the 13th of August, the GDR closes the open borders between East Berlin and West Berlin. Berliners wake up in shock to find a wall running down through the middle of their city, with many citizens having jobs and families on the other side. The wall is extremely guarded and East Berliners are effectively stripped of their freedom of movement.