Filmed in Technicolor, Thunderbolt was the last of Major William Wyler's wartime directorial efforts on behalf of the US Army Air Corps. As in his previous WW2 documentaries, Wyler himself participated in the mission that he depicts herein on film. The title refers to the huge bombers used by the Corsica-based 57th fighter group. The film concentrates on "Operation Strangle," the all-out assault agains t the Nazi stronghold at Monte Cassino. Adding poignancy to the film is the knowledge that several of the extremely young American participants, here shown smiling and waving at the camera, did not survive the battle. Released to the troops in 1945, Thunderbolt was distributed theatrically in 1947.