Warren was commissioned as a colonel in the United States Army Medical Corps in 1943 and appointed Chief of the Medical Section of the Manhattan Engineering District . He was responsible for the health and safety of the thousands of personnel involved in the Manhattan Project . He was present at the Trinity nuclear test in Alamogordo , New Mexico where he was responsible for the safety aspects of the detonation of the world 's first nuclear weapon . He led a survey team from the Manhattan Project to assess the effects of the atomic bombings of Hiroshima and Nagasaki . In 1946 he was Chief of the Radiological Safety Section of the Joint Task Force for Operation Crossroads , the nuclear test at Bikini Atoll
Trinity nuclear test
Trinity (nuclear test)
Stafford L. Warren