Dick Butkus, the legendary Chicago Bears linebacker, has died, his family said. He was 80.Butkus "died peacefully" in his sleep overnight at his home in Malibu, California, his family said in a statement Thursday."The Butkus family is gathering with Dick's wife Helen," the statement continued. "They appreciate your prayers and support."Bears chairman George McCaskey said Butkus was "one of the greatest players in NFL history" and exuded "toughness, smarts, instincts, passion and leadership.""His legacy of philanthropy included a mission of ridding performance enhancing drugs from sports and promoting heart health," McCaskey said in a statement. "His contributions to the game he loved will live forever and we are grateful he was able to be at our home opener this year to be celebrated one last time by his many fans." NFL Commissioner Roger Goodell said Butkus was a "fierce and passionate competitor who helped define the linebacker position as one of the NFL's all-time greats.""Dick's intuition, toughness and athleticism made him the model linebacker whose name will forever be linked to the position and the Chicago Bears," Goodell said in a statement.