The Harvard-educated mathematician led a 17-year campaign of terrorist attacks that killed three people and wounded 23 others. His manhunt was the longest and costliest in the country, according to the FBI.
Kaczynski was found unconscious in his cell Saturday morning and pronounced dead around 8 a.m. He had been held at Supermax federal prison in Florence, Colorado, since May 1998, when he was sentenced to four life terms plus 30 years for a terror campaign that put universities across the country on edge.