Following the annexation of Austria and the Sudetenland, Germany in October 1938 urged the Danzig territory's cession to Germany. On 1 September 1939 Nazi Germany invaded Poland, initiating World War II. On 2 September 1939 Germany officially annexed the Free City. The Nazi regime murdered the Polish postmen defending the Polish Post Office: this was one of the first war crimes during the war. Other Polish soldiers defending the Westerplatte stronghold surrendered after seven days of fighting. The German commander returned the sword to the Polish commander for putting up a brave fight, while the same time one the captured defenders, Kazimierz Rasinski was brutally tortured by Germans and murdered when he refused to reveal Polish communication codes. On Sep 7th NSDAP organised night parade on Adolf-Hitlerstrasse to celebrate success. It was bombed by a single Polish hydroplane operating from Hela peninsula piloted by Jozef Rudzki and Zdzisław Juszczakiewicz. Six bombs each weighing were dropped from very low height.