Kelley Mack, who played Hilltop resident Addy on 'The Walking Dead' and appeared in Dr Pepper's 'Fansville' ads, dies of a rare form of cancer at age 33.

Actress Kelley Mack, known for her appearance in post-apocalyptic zombie drama “The Walking Dead,” has died. She was 33.

After Kelley Mack died at age 33 following a battle with cancer, her Walking Dead costars paid tribute to the late actress.