On June 5, 2009, Barack Obama makes a special visit to Buchenwald concentration camp in central Germany -- a public gesture of commemoration, and a personal tribute to his great-uncle, who as a U.S. soldier helped liberate the camp. Here, in one of the most haunting images from the war, taken in April 1945 by LIFE photographer Margaret Bourke-White, prisoners at Buchenwald gaze dully at the Allied troops arriving at the camp, unable to comprehend that freedom has, finally, come. WARNING: Several of the images in this gallery are intensely graphic, depicting scenes of violence and death.