Frank Calabrese Sr - the infamous Chicago hit man - has died in a federal prison in North Carolina, Fox News Reports. Calabrese Sr reportedly would strangle his victims, then slit their throats to ensure they were dead.

Although heart problems are thought to be at the root of his death, considering cardiovascular problems were a stated problem of his, Ed Ross, a spokesman for the Federal Bureau of Prisons, has no information on his death. "It's very emotional right now because there were two sides to my dad, and I miss the good side," Calabrese's son Frank Calabrese Jr. told the Chicago Sun-Times. Frank is actually one of the reasons for Calabrese Jr's prison sentence, as he recorded his father boasting about mob killings. Years went into trying to take down the Chicago Outfit, which culminated with 5 arrests in 2007, including Calabrese Sr. His Christmas day passing, according to his son, was meant to be. "I believe he was taken on Christmas Day for a reason," he said. "I hope he made peace. I hope he's up above looking down on us. ... He's not suffering anymore. The people on the street aren't suffering anymore."

Chicago Crime Commission Executive Vice President Art Bilek said of him, "I would say that Frank was the last of his kind of fellow who came up the ranks the hard way: breaking people's skulls and knees and graduating to murder. . . . He was the youngest of the old-timers, all but ending that generation."