Atomic Bomb (Fallout 3)

The Megaton Atomic Bomb (called Atom by the The Church of the Children of Atom and also the Apostles of the Holy Light) is the undetonated Vault-Tec Industries C-23 Megaton nuclear weapon sitting at the center of Megaton. The fate of the bomb and the whole settlement is determined in one of the adventures of the Lone Wanderer.

Background
The bomb was dropped on Washington, D.C. during the Great War in 2077; however, it remained undetonated in its crater. The founders of Megaton discovered the bomb, and a group of people calling themselves the Children of the Atom started worshipping it. Both groups teamed up, and, using airplane parts from a demolished airport, built Megaton's walls and structures and settled in the area.

The bomb is still active, and, in 2277, the Lone Wanderer is given the choice to detonate it (destroying Megaton in the process), or disarm it and save the town's population. Mister Burke is the person who is looking for help detonating it, as his employer, Allistair Tenpenny, considers Megaton "a blight on the landscape" of the Capital Wasteland. Megaton's sheriff Lucas Simms offers a reward for disarming the bomb. The fate of the town lies in the Lone Wanderer's hands.

Characteristics
The atomic bomb itself is in the center of the town, since Megaton was built around the crater in which it sits. It lies in a puddle of radioactive water from which Confessor Cromwell is constantly making speeches about his religion.

The bomb can be rigged to detonate with a fusion pulse charge.

Located near the tip of the bomb (facing the Church), a biological hazard symbol is barely recognizable.

Outside of Megaton
After taking part of the Ritual of the Mother Seed inside Point Lookout's Sacred Bog, the Lone Wanderer sees the bomb sitting next to Mister Break during the punga-infused hallucination. Although similar to the real bomb in Megaton, the imaginary one is much larger. After an interaction with Mr. Break, the bomb explodes and the Lone Wanderer wakes up outside of the Sacred Bog.

Appearances
The Megaton atomic bomb only appears in Fallout 3.

Behind the scenes
The Megaton bomb is modeled after the "Fat Man" bomb, one of the world's first three functional nuclear weapons. "Fat Man" was dropped on the Japanese city of Nagasaki.