"Unabomber" Theodore Kaczynski was found dead in a federal prison in North Carolina. He was serving a life sentence for a series of bomb attacks on scientists.
He pleaded guilty to triggering 16 explosions that killed three people and injured 23 others. The cause of his death is unknown, the U.S. Bureau of Prisons says. He had been transferred to the federal prison's medical facility after spending two decades in a Supermax prison in Colorado for the attacks. The FBI is investigating the death.