Polish submarine sunk by German forces according to a report of the American Naval Attaché at Berlin, Germany Nr. R562 dated 15 September 1939

Diary note dated Tuesday 5 September 1939. An item reported that German forces sunk a third Polish submarine.

Source

National Archives. FDR Presidential Library&Museum Roosevelt PSFC000175. War diary Naval Attaché Berlin, volume 1 (1 September 1939-26 May 1940)