On April 13, 1945, German SS and Luftwaffe troops, retreating from the Allied advance, murdered 1016 political and military prisoners near the German town of Gardelegen. The crime was discovered two days later by F Company, 2d Battalion, 405th Regiment, U.S. 102nd Infantry Division.
More info:
http://www.ushmm.org/wlc/article.php?lang=en&ModuleId=10006173
http://www.gardelegen.info/uk/geschichte_gedenkstaette.htm