American football linebacker and defensive end Kevin Greene died Monday, at the age of 58. The cause of his death has not been announced.

Greene played for the Los Angeles Rams, Pittsburgh Steelers, Carolina Panthers, and San Francisco 49ers of the National Football League between 1985 and 1999.

His historic levels of success came more from his determination and passion for the game. He was a character for the autumns. He was one of the most prolific pass rushers to ever grace the gridiron.

Greene’s 15-season NFL career was highlighted by 160 sacks, which stands as the third-highest total in league lore, according to NFL.

Carl David Backer, President and CEO of the Pro Football Hall of Fame, said in a statement, “The entire Pro Football Hall of Fame family mourns the passing of Kevin Greene.”

“I regarded him as a personal friend and a true Hall of Famer in every sense. He possessed the most incredible can-do attitude of anyone I ever met. He was a great player, but more than that, he was a great man.”

“Our thoughts and prayers are with Kevin’s wife, Tara, and their entire family. We will forever keep his legacy alive to serve as inspiration for future generations,” Baker added. “The Hall of Fame flag will be flown at half-staff in Kevin’s memory.”

Art Rooney Sr., President of Pittsburgh Steelers, said, “We lost an amazing player and person this morning with the passing of Kevin Greene. His sudden death is a shock to us all as he was a close friend and teammate to so many people in the Steelers family.”

“When Kevin came to the Steelers in 1993 he had an immediate impact,” he continued. “Paired with Greg Lloyd, Kevin and Greg led a defense that became known as Blitzburgh and went on to play in Super Bowl XXX. Kevin’s energy and enthusiasm were inspiring for our team as well as our fans.”

“My condolences go out to Kevin’s wife, Tara, their children and the entire Greene family in this most difficult time,” Rooney added. “They will always be members of the Steelers family and in our thoughts and prayers.”

Greene also dabbled in pro wrestling, joining the World Championship Wrestling while he was still with NFL. “He was larger than life, loud in all that he did in the arena,” according to NFL.

Born on July 31, 1962, in Schenectady, New York, Greene was an army brat and began playing football on military bases. He and his wife, Tara, had a son, Gavin, and a daughter, Gabrielle.