Theodore "Ted" Kaczynski, a Harvard-educated mathematician who conducted a 17-year bombing campaign that killed three people and injured twenty-three others, passed away on Saturday. He was 81.

Kaczynski, dubbed the "Unabomber" by the FBI, passed away at the federal penitentiary medical center in Butner, North Carolina, according to Kristie Breshears, a spokesperson for the federal Bureau of Prisons. She stated that he was discovered unresponsive in his cell on Saturday morning and pronounced deceased around 8 a.m. The cause of death was initially unknown.

Before his transfer to the prison medical facility, he had been incarcerated in the federal supermax prison in Florence, Colorado, since May 1998, when he was sentenced to four life sentences plus 30 years for a terror campaign that shook university campuses. He admitted to perpetrating 16 bombings between 1978 and 1995, leaving several of his victims permanently disfigured.

In a campaign against what he believed to be the evils of modern technology, the Harvard University graduate targeted academics, scientists, and computer store proprietors and even attempted to blow up a commercial airliner. For years, he hindered police efforts to identify the killer by providing no firm leads.

In July 1995, the Unabomber's lethal homemade explosives altered how Americans mailed packages, boarded airplanes, and virtually halted air travel on the West Coast.

In September 1995, he forced The Washington Post and The New York Times to decide to publish his 35,000-word manifesto, Industrial Society and Its Future, which asserted that modern society and technology led to feelings of helplessness and alienation.

However, it leads to his demise. David and Linda Patrik, Kaczynski's brother and sister-in-law, recognized the tone of the manifesto and tipped off the FBI, which had been seeking the Unabomber for years in the nation's longest and most expensive manhunt.

In April 1996, authorities discovered him in a 10-by-14-foot (three-by-four-meter) plywood and tarpaper cabin outside Lincoln, Montana, containing journals, a coded diary, explosive ingredients, and two completed devices.

As a fugitive criminal mastermind, the Unabomber garnered much support and comparisons to Daniel Boone, Edward Abbey, and Henry David Thoreau.

Once revealed as a wild-eyed recluse with long hair and a beard who survived Montana winters in a one-room shack, Kaczynski struck many as a pitiful loner rather than a romantic anti-hero.