Kansas City, MO -- (Sports Network) - Darvin Wallis, a former assistant coach with the Kansas City Chiefs, passed away at the age of 60 on Wednesday.

Wallis served as a defensive assistant/quality control coach with the Chiefs for 19 years, which ranked as the second-longest stint by an assistant coach in franchise history, second to only Tom Pratt who served for 21 years.

Wallis also joined Pratt as the only assistant coach in franchise history to serve under four different head coaches. Wallis served under Marty Schottenheimer, Gunther Cunningham, Dick Vermeil and Herm Edwards.

"On behalf of my family and the entire Chiefs organization, we want to extend our deepest sympathies to Vicky and the Wallis family during this difficult time," said Kansas City owner Clark Hunt said. "Darvin worked tirelessly behind the scenes for the Chiefs for nearly 20 years. He was a beloved figure at Arrowhead, and we will always remember and appreciate his lasting contributions to our team."

Wallis began his coaching career with the Cleveland Browns in 1982.