Former Chicago Bears linebacker and Pro Football Hall of Famer Dick Butkus has died at the age of 80, the team announced Thursday.

Butkus died "peacefully in his sleep overnight at home in Malibu," California, a statement from his family, posted by the Bears on social media, reads.

A ferocious hitter, Butkus was an imposing force as the Bears' middle linebacker for nine seasons in the 1960s and 1970s, and made eight Pro Bowls.

He retired after playing part of the 1973 season, a few years after suffering a knee injury, and was elected to the Pro Football Hall of Fame in 1979, his first year eligible.

This is a developing story and will be updated.