The weapons store that the inmates had collected found a use on 11 April 1945 when Gronau participated in a "self-release" operation with other Buchenwald camp inmates. By this time, from the perspective of any guards who had not fled in response to the report of atrocities committed by the Red army advancing rapidly from the east, the camp was being evacuated by the German government, and there are reports of many thousand inmates being forced to join the evacuation marches, but Gronau appears not to have been among these. War ended, formally, during the first week of May 1945. Heinz Gronau made his way home to Leipzig, which had been liberated from National Socialism by US forces during April 1945. However, the leaders of the United States and Soviet Union had already agreed between them a post-war division of Germany whereby the whole of Saxony would be administered by the Soviet Union. In July 1945 US forces therefore withdrew from Leipzig and the surrounding region, leaving the city to which Gronau had returned administered as part of the Soviet occupation zone. During 1945/46 he was placed in charge of the city's social and youth welfare office.