Kurt Gruber was a German coal miner from the Ruhr Valley, a communist militant who fled Nazism in his country and was trained by the OSS, which later became the CIA, to spy in Germany, during WWII.
He was killed when the US Air Force plane carrying him to his destination in the Ruhr Valley crashed in bad weather, on 20 March 1945. His remains are buried in the US Military Cemetery in Neuville-en-Condroz, Belgium.
Source: "The OSS and the London "Free Germans" by Jonathan S. Gould
"Find the cost of freedom, buried in the ground,
Mother Earth will swallow you,
Lay your body down."