Benjamin Bederson, a New York native, was selected to serve in the Special Engineering Detachment during the Manhattan Project. A physicist, he was first sent to Oak Ridge, and then to Los Alamos, where he worked for Donald Hornig on designing the ignition switches for the implosion bomb. At Los Alamos, he knew Ted Hall and David Greenglass, who were secretly sending atomic bomb secrets to the USSR. Bederson instructed the 509th Composite Group at Wendover and was sent to Tinian to help wire the switches for the bomb. He recalls the feeling of expectation just before the bombing of Hiroshima and his jubilation at Japan’s surrender. Bederson’s story is currently featured at the New-York Historical Society exhibition WWII & NYC.