Peter Newport Bragg, Jr. served as a civilian engineer working for the U.S. Navy beginning in 1944. A brilliant chemical engineer, he volunteered for a dangerous assignment while employed by the U. S. Navy Research Laboratory's "pilot-plant" at the Philadelphia Navy Yard. As a part of the Manhattan Project, it was the Lab's mission to perfect the thermal diffusion process for the enrichment of uranium. On Sept. 2, 1944, while working to unclog a tube in a complex array of pipes, Peter was killed in a horrific explosion that sent a cloud of radioactive uranium hexafluoride over much of the Navy Yard including the battleship USS Wisconsin, berthed just 200 yards away. A fellow co-worker, Douglas Meigs, was also killed. His work and that of the Naval Research Laboratory was crucial to the development of the first atomic bomb. You can read more about the tragic accident in Philadelphia here.