Flynn arrived in South Vietnam in January 1966, as a free-lance photojournalist; first for the French magazine Paris-Match, then for Time-Life and finally for United Press International. His photos were soon published around the world. He soon made a name for himself as one of that group of high-risk photojournalists who would do anything to get the best pictures; even going into combat. On April 6, 1970, while travelling by motorcycle in Cambodia, Flynn and Dana Stone (on assignment for Time magazine and CBS News respectively) were captured by communist guerrillas at a roadblock on Highway One. They were never heard from again and their remains have never been found. The consensus is that they were both killed by Khmer Rouge in June 1971.