Fifty-five prisoners died before the outbreak of World War II in September 1939. During mid-1939, Nazi authorities planned to invade Poland. It was decided to stage false flag attacks in order to justify a German declaration of war. Several prisoners from Flossenbürg and other concentration camps were secretly transferred to a Gestapo prison in Breslau, poisoned, and dressed in Polish uniforms. On 31 August 1939, the bodies were dumped at a border post in Hochlinden where they were shot and hacked; photographs were taken as "proof" of a Polish attack on Germany.