He was 81, and died in federal prison after 20 years of being there.

AP

Part of the article:

WASHINGTON (AP) — Theodore “Ted” Kaczynski, the Harvard-educated mathematician who retreated to a dingy shack in the Montana wilderness and ran a 17-year bombing campaign that killed three people and injured 23 others, died Saturday. He was 81.

Branded the “Unabomber” by the FBI, Kaczynski died at the federal prison medical center in Butner, North Carolina, Kristie Breshears, a spokesperson for the federal Bureau of Prisons, told The Associated Press. He was found unresponsive in his cell early Saturday morning and was pronounced dead around 8 a.m., she said. A cause of death was not immediately known.

Before his transfer to the prison medical facility, he had been held in the federal Supermax prison in Florence, Colorado, since May 1998, when he was sentenced to four life sentences plus 30 years for a campaign of terror that set universities nationwide on edge. He admitted committing 16 bombings from 1978 and 1995, permanently maiming several of his victims.

Years before the Sept. 11 attacks and the anthrax mailing, the Unabomber’s deadly homemade bombs changed the way Americans mailed packages and boarded airplanes, even virtually shutting down air travel on the West Coast in July 1995.

He forced The Washington Post, in conjunction with The New York Times, to make the agonizing decision in September 1995 to publish his 35,000-word manifesto, “Industrial Society and Its Future,” which claimed modern society and technology was leading to a sense of powerlessness and alienation.

But it led to his undoing. Kaczynski’s brother, David, and David’s wife, Linda Patrik, recognized the treatise’s tone and tipped off the FBI, which had been searching for the Unabomber for years in nation’s longest, costliest manhunt.

A primary school teacher I had looked like that Unibomber sketch and my family tree would always find my kid retelling of this so amusing at gatherings.

"Come here! Okay tell them who your teacher looks like"