Shot Bee was the sixth nuclear detonation of Operation Teapot, fired on 22 March 1955 from a 152-metre tower in Area 7 of Yucca Flat, Nevada Test Site. It was a Los Alamos Scientific Laboratory development test of the XW-25 — a sealed-pit DT gas-boosted fission warhead designed for air defence applications. With a nuclear system weighing just 59 kg and measuring 43 centimetres in diameter, it was at the time of its detonation the smallest and lightest nuclear device ever tested. The maximum predicted yield was 20 kilotons; the actual yield was 8 kilotons. An augmented Marine Corps unit participated in the Desert Rock VI exercise at Shot Bee, observing the detonation from 10 kilometres southwest of ground zero as part of the ongoing programme to train military forces for operations on a nuclear battlefield. This AEC photograph — AEC-55-5191 — is credited to the Joint Office of Test Information.