The U.S. Defense Department on Friday said the remains of an airman lost on the famous "Hump Route" during World War II have been identified and are being returned to his family for burial with full military honors.

The remains were of U.S. Army Air Forces Pfc. Mervyn Sims, who was 23 at the times when he was missing. He will be buried Friday in his hometown of Petaluma, California.

On April 24, 1943, Sims and four crew members aboard a C-87 Liberator Express departed from Yangkai, China, in support of "the Hump" resupply mission between India and China. Prior to takeoff, a ground crew determined the aircraft had sufficient fuel for the six-hour flight to the air base on other side of the Himalayas in Chabua, India. Once cleared for takeoff, there was no further communication between the aircrew and airfield operators.

Army officials launched a search effort when the plane did not arrive at the destination. No evidence of the aircraft was found and the five men were presumed killed in action. Sim's remains were found in 2003 in Myanmar.

The Chinese and American air forces opened an air supply route over the Himalayas known as "the Hump" in 1942. The route was a major airborne passage for Chinese and the Allied forces during the war.

More than 500 airplanes were lost on the "Hump Route." More than 3,300 airmen, including 1,500 Americans, died in action.

Of the 16 million Americans who served in World War II, more than 400,000 died. At the end of the war, the U.S. government was unable to recover and identify approximately 79,000 Americans. Today, more than 72,000 are unaccounted for from the conflict.