Here, we see children riding the casing for a nuclear weapon.
The casing is like the one that contained Fat Man, one of the two nuclear bombs that the United States dropped on Japan at the end of World War II. Americans deployed the original Fat Man on Nagasaki, where it killed an estimated 74,000 people. The casing you see above is located at White Sands Missile Range, near the Trinity Site, where the first Bomb was tested.
Via Alex Wellerstein, nuclear historian at the American Institute of Physics