Second Lieutenant Calkins was the radio operator of a B-29 Superfortress Bomber with the 98th Bomb Wing at Anderson Force Base, Guam. On 13 June 1952, his aircraft was flying about 90 miles west of Kwajalein Atoll, Marshall Islands, when it developed engine trouble, crashed and sank immediately into the ocean.

Calkins was awarded an accolade signed by President Harry Truman and the National Defense Service Medal.