Theodore “Ted” Kaczynski, better known as the Unabomber, has been found dead in his cell at the Butner federal prison in North Carolina (USA) at the age of 81. Kaczynski, a mathematician, philosopher, and terrorist—and known for his Unabomber manifesto—was serving eight life sentences without review for sending 16 letter bombs over 17 years to universities and airlines from a shack in the Montana desert. killing three people and injuring 23 between 1978 and 1995.

Classified as an FBI Unabomber, Kaczynski died at the federal prison medical center, penitentiary sources have told The Associated Press. The terrorist was found unconscious in his cell early Saturday morning and was pronounced dead around 8:00 a.m. At the moment, the cause of death is unknown.

Prior to his transfer to the prison medical center, he had been held at the Supermax Federal Prison in Florence, Colorado, since May 1998, where, to avoid the death penalty and after a plea bargain, he was serving his eight sentences. consecutive terms of life in prison without the possibility of parole.

He admitted to committing 16 bombings between 1978 and 1995, permanently maiming several of his victims. Years before the 9/11 attacks and anthrax mailing, the Unabomber’s deadly pipe bombs changed the way Americans mailed packages and boarded planes, even virtually shutting down air travel on the West Coast in July 1995.

He forced The Washington Post, along 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 asserted that modern society and technology were leading to a feeling of helplessness and alienation.

This led to his downfall. Kaczynski’s brother, David, and David’s wife, Linda Patrik, recognized the tone of the treaty and alerted the FBI, which had been searching for the Unabomber for years in the country’s longest and most expensive manhunt. In April 1996, authorities found him in a 10-by-14-foot (3-by-4-meter) plywood and tar paper shack outside Lincoln, Montana, filled with newspapers, a coded journal, explosive ingredients, and two full bombs.

As an elusive criminal mastermind, the Unabomber earned his share of supporters and comparisons to Daniel Boone, Edward Abbey, and Henry David Thoreau. But once revealed as a wild-eyed hermit with long hair and a beard who weathered Montana winters in a one-room shack, Kaczynski seemed to many more a pathetic loner than a romantic antihero.