Building upon the cyclotron, Lawrence’s calutrons — hybrids of the cyclotron and a mass spectrometer — were created for the the Manhattan Project for electromagnetic separation of uranium isotopes. The Y-12 plant at Oak Ridge, containing these massive calutrons “racetracks” using over 14,700 tons of silver, enriched the uranium-235 and shipped the first few hundred grams to Los Alamos laboratory in March 1944.
The USS Indianapolis left Hunters Point Naval Shipyard on July 16, 1945, setting a speed record of 74-1/2 hours from San Francisco to Pearl Harbor, arriving on July 19. She was on a top-secret mission carrying the enriched uranium from Oak Ridge and other assembly parts for the “Little Boy” atomic bomb.
Indianapolis continued on to Tinian, arriving on July 26, and delivered the atomic bomb components. Continuing on to Guam for crew changes, she left on July 28 to begin sailing toward Leyte to join Task Force 95.
On July 30, 1945, Indianapolis was truck by two torpedoes from a Japanese submarine, causing massive damage. Twelve minutes later, she sunk, taking 300 crew down with her and setting adrift over 900 crewmen.
On August 2, the survivors were spotted by Navy airplanes on a routine patrol flight. Only 316 of the remaining men survived.
You can visit the memorial for the USS Indianapolis located at the north end of the Canal Walk between Senate Avenue and Walnut Street. The gray and black granite memorial is outdoors and open to the public.
General Groves oversaw the construction of the Pentagon, but more notably, directed the Manhattan Project that developed the atomic bomb during World War II.
Groves died on July 13, 1970, at 73 years of age. He is interred in Arlington National Cemetery, next to his brother, Allen, who died of pneumonia in 1916. Grace, his wife, was interred next to Groves in 1986.
The tombstone marks his participation in the Manhattan Project along with the insignia. The grave faces the Pentagon, which can be seen in the distance.