Enlisted in the Army Air Corps on 22 December 1943 at Jefferson Barracks near St. Louis, Missouri. He received training as an Aerial Gunner, and was subsequently assigned to the 504th Bombardment Group (Very Heavy) for advanced training with B-29 aircraft at Fairmont Army Air Field near Geneva, Nebraska.

On 23 December 1944, the 504th BG deployed to the Pacific Theater of Operations. CPL Dunn was assigned to the 20th Air Force, XXI Bomber Command, 313th Bombardment Wing, 504th Bombardment Group (VH), 398th Bomb Squadron; being stationed at North Field, on Tinian in the Mariana Islands.

They deployed from Mather Field, Sacramento, California, which was the aerial port of embarkation, to John Rodgers Field on Oahu in the Hawaiian Islands (a 10-hour flight, some 2,460 miles). The next leg to Kwajalein Atoll in the Marshall Islands was about as long a flight (2,100 miles). Kwajalein to Tinian was a shorter flight (approximately 1,550 miles).

In January 1945, the 504th BG began combat operations from Tinian with attacks on Japanese airfields and other installations on Maug and Iwo Jima and in the Truk Islands.

On 4 February 1945, the 504th BG flew its first mission against the Japanese home islands when the group bombed the industrial area of Kobe, Japan (20th AF Mission #26, code named: Middleman #1). These were 15-hour sorties (approximately 2,950 miles round-trip).

On 10 February 1945, he flew as an aerial gunner in the right scanner blister station aboard a Boeing B-29 Superfortress (Tail #42-24790). 504th BG aircraft were also identified by an "E" inside a “Circle” painted on the tail. It was one of 120 aircraft launched in a multi-wing group formation to bombard the Nakajima Aircraft Assembly Plant at Ota on the northwest side of Tokyo, Japan.

While over the target area, the Group was attacked by a band of Nakajima KI-44 single-engine 'Tojo' fighter planes. His B-29 aircraft suffered heavy damage to one of the wings, and on the return route home was forced to ditch approximately 275 miles north of Tinian, near Pagan Island.

Last contact was by an air-sea radio call at an approximate geographic location of: 19 degrees 9 minutes North, 145 degrees 18 minutes East. The pilot had previously expressed an opinion that the plane could make it back to the base OK. Although not an eye-witness, one of the other returning B-29 aircraft did report hearing a large explosion in the vicinity. Approximate time would have been about 22:18 PM. Weather was reported as solid overcast above a 1200-foot ceiling. An immediate air-sea rescue search of the area failed to reveal any trace of the aircraft or crew members.

The aircrew was initially listed as missing in action (MIA). Their status was changed from MIA to Killed In Action (KIA) one year later on 11 Feb 1946. The aircrew is remembered on the Tablets of the Missing, Honolulu Memorial Cemetery, Hawaii.

Hartford H Dunne