Cpl. Hasenfus served with the 10th Special Forces Group. At some point between 1983-84, he was part of one of the 17 Mobile Training Teams sent into Lebanon to advise and train the Lebanese army.
Corporal Hasenfus. One source states that he was a victim of the barracks bombing in Beirut, Lebanon, and may have lingered for some time before succumbing to his wounds. Another source states that he took his own life. If true, he did so as the first anniversary of the Beirut bombing occurred (3 days prior). An educated guess might be that he succumbed to PTSD, specifically survivor guilt over not perishing in the bombing.
Still, anything is a guess. What is known is that he servedc his country in a foreign land to the best of his ability, during trying times.