In 1942, Oppenheimer was hired to work on the Manhattan Project. In 1943 he became director of the project's Los Alamos Laboratory in New Mexico. His job was to help create the first nuclear weapons with other scientists and General Leslie Groves. On July 16, 1945, he was present at the first test of the atomic bomb, Trinity. In August 1945, the weapons were used against Japan in the bombings of Hiroshima and Nagasaki.