WATCH: In 1986, the Government Made a Terrifying Fake TV Report About a Nuclear Attack on U.S. City

In December of 1986, the Pentagon, the CIA, FBI, the Department of Energy, and just about every other federal agency you can think of came together in Indianapolis for an enormous training exercise code-named Mighty Derringer. The plan was to simulate a nuclear terrorist incident and explore how every agency would react and whether they would cooperate. To enhance the verisimilitude of the war games, the U.S. government went so far as to record a fake news broadcast about a nuclear bomb exploding in Indianapolis.

Until now, no one outside of the government has seen the video.

Gizmodo obtained the Mighty Derringer footage through a Freedom of Information Act request with the National Nuclear Security Administration (NNSA), which operates under the Department of Energy.

As you can probably guess from the name, the NNSA’s work is serious business. When the U.S. started to see a sharp rise in terrorist threats in the early 1970s involving nuclear material (or at least claims of nuclear material), the NNSA formed the Nuclear Emergency Search Team, or NEST, in 1974. The team’s mandate was to stand at the ready to deploy a group of experts to anywhere in the country on a moment’s notice in response to threats that mentioned nuclear material. And when large public events happened and nuclear experts were needed just in case, NEST team members were the people who mobilized surveillance vehicles, helicopters, and other special equipment to sweep for anything radioactive.  – READ MORE