U-96(Heinrich Lehmann-Willenbrock) back in St. Nazaire, France from its 9th patrol of 52 days, claiming 5 ships for 25,464 GTR, 23 March 1942.
( Bundesarchiv Bild 101II-MW-3712-04A)

U-96

Fregattenkapitän Reinhard "Teddy" Suhren (1916-1984)
http://en.wikipedia.org/wiki/Reinhard_Suhren

Reinhard Suhren (col.)

The "Wilhelm Gustloff" was constructed as for the German Labour Front as a "Strength through Joy" ship, intended to provide short pleasure cruises for deserving German workers and Nazi Party officials.  It performed this function between 1937 and 1939, when it was appropriated for military use, starting with transporting elements of the Condor Legion back to Germany from Spain.  The ship subsequently served as a floating hospital, a floating barracks and, latterly, as a transport.  In the latter capacity, it was employed in "Operation Hannibal", the (on the whole remarkably successful) operation to transport German service personnel and civilians from Germany's surviving Baltic enclaves to the West, January to May, 1945.  

The "Wilhelm Gustloff" left Gotenhafen for the West on 30 January, 1945.  Its official complement was about 6,000, substantially composed of military personnel.  However, it has been determined that the ship was actually carrying more than twice that number, the balance composed of German civilians not officially recorded on the ship's manifest.  As a military transport, carrying light defensive armament, it was not in any sense a Red Cross transport, and was not marked as such.

At about 21.00 hours, Central European Time, on 30 January, the "Gustloff" was spotted by Soviet submarine S-13, comanded by Soviet submarine ace Alexander Marinesko.  Marinesko saw no reason to doubt that this was a legitimate target, and attacked, hitting the ship with three torpedoes.  Within three quarters of an hour, the ship had sunk.  German naval vessels managed to save a small number of the survivors; however, it has been estimated that some 9,400 persons from the "Wilhelm Gustloff" died that night, mainly from hypothermia in the freezing Baltic waters.

This incident is generally recognised as having involved the greatest loss of human life in any known ship sinking, putting the case of the "Titanic" (the centenary of whose sinking is currently being commemorated) firmly in the shade.

May the souls of those who died a horrible death on that freezing night rest in peace.  In sadness, JR.