The Struma was a ship charterd by the Revisionist Zionist organization in Romania (especially Betar) to bring Jewish refugees from Axis–controlled Romania to Allied-controlled Palestine.
It was, so-to-speak, in British eyes an “illegal” immigrant ship. The Stürma was a former coal barge–turned–rescue ship, and although not seaworthy, loaded 769 passengers at Constanza, Romania on December 12, 1941 and headed towards Palestine.
The ship reached Istanbul, Turkey, but the passengers were not permitted to land until the British would issue assurances that they would be allowed to proceed to Palestine. The British refused to allow them to land under the White Paper agreement of 1939.
After two months of pressure, the British relented and agreed to allow children to leave the ship. Although they promised to notify the Turks, they delayed for 10 days. Giving up, the Turks had the boat, still loaded with its 769 Jewish passengers, towed out to the Black Sea. It was torpedoed by Soviet submarine Sch 213 acting under orders to sink all neutral or Axis shipping entering te Black Sea – in order to deny potential supplies to Germany. 768 of the 769 Jewish passenger-refugees perished.