SS Mary Luckenbach (1919)

SS Mary Luckenbach (ID-3861), was a cargo ship of the United States Navy. She was built in 1918 and 1919 by the American International Shipbuilding Corp., Hog Island, Pennsylvania as USS Sac City.

Service history
The USS Sac City was commissioned in the Navy on 6 January 1919. At the end of January 1919, the ship sailed from Norfolk, Virginia, with a cargo destined for Montevideo, Uruguay. The ship arrived in Uruguay at the beginning of March 1919. She moved to the nearby port of Rosario, and loaded a private commercial cargo, which was taken to Gibraltar. The freighter sailed to New York City from Gibraltar in June 1919. USS Sac City was decommissioned on 17 June 1919 and sent to the U.S. Shipping Board. During her subsequent commercial service she was renamed SS Black Falcon in 1932 and SS Mary Luckenbach in 1941. While en route to Murmansk, USSR, as part of Convoy PQ-18, the ship was sunk. She was hit by an aerial torpedo dropped by a German aircraft west of North Cape, Norway, on 13 September 1942. This resulted in the detonation of the ship's cargo of high explosives. The ship was totally destroyed, killing all of the 41 merchant mariners and 24 U.S. Navy armed guardsmen on board.

World War II
In September 1942, the SS Mary Luckenbach was part of convoy PQ-18. It was traveling through the Barents Sea en route to Murmansk, Russia. PQ-18 contained over 40 merchant ships that were under heavy escort. During the voyage 13 of the ships, including the Mary Luckenbach, were sunk.

On 14 September 1942 (some sources list 13 September), the ship was attacked by several German aircraft, and was hit by an aerial torpedo. The impact of the torpedo struck the ship's cargo of 1,000 tons of TNT. The explosion was so violent the ship was basically vaporized along with the entire crew. The last known location of the ship was 75 degrees north, 10 degrees east.