On 16 January 1945 Colonel Bogislaw von Bonin, the Chief of the Operational Branch of the Army General Staff ("Generalstab des Heeres") gave Army Group A permission to retreat from Warsaw, overruling a direct order from Hitler for them to hold fast. Three days later von Bonin was arrested by the Gestapo and imprisoned first at Flossenbürg concentration camp and then Dachau concentration camp. The officer was eventually liberated along with other prisoners in South Tyrol by the US Army in May 1945.