The 509th Composite Group (509 CG) was a unit of the United States Army Air Forces created during World War II and tasked with the operational deployment of nuclear weapons. It conducted the atomic bombings of Hiroshima and Nagasaki, Japan, in August 1945. The 509th Composite Group began deploying to North Field on Tinian, Northern Mariana Islands, in May 1945. In addition to the two nuclear bombing raids, it carried out 15 practice missions against Japanese-held islands, and 12 combat missions against targets in Japan dropping high-explosive pumpkin bombs.