 Graves and Elizabeth moved to work at Los Alamos Laboratory in New Mexico when it opened in 1943. He made it a condition of his going to Los Alamos that a job be found there for her. This was probably unnecessary, as someone with her skills — she was one of the few physicists who had experience with a Cockcroft-Walton accelerator — would have been quickly snapped up at Los Alamos. At the time of the Trinity nuclear test in 1945, Elizabeth was seven months pregnant with her first child. Graves therefore requested that they be assigned to a post far from the blast. They listened to Samuel K. Allison's countdown to the explosion on the radio, and monitored the radioactive fallout from the test, which took until the afternoon to reach them, with Geiger counters. The child was a healthy daughter, Marilyn Edith.
