Barack Obama's campaign says the candidate made a mistake when he said a great uncle helped liberate the Nazi death camp at Auschwitz during World War II. Obama said Monday that his uncle was among the first US troops at Auschwitz. But Auschwitz was liberated by Soviet forces. The campaign said Tuesday that he named the wrong camp. They said it was actually Buchenwald. Aides said his grandmother's brother, Charlie Payne, helped liberate a Buchenwald sub-camp in April 1945 as part of the 89th Infantry Division.