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.

Kelley Mack, an actress best known for her work on the horror series “The Walking Dead,” has died at age 33. A representative for Mack confirmed her death to ABC News and said in a statement, “She will be so missed.”

Kelley Mack, who played Addy on The Walking Dead, died Aug. 2 following a battle with a rare type of astrocytoma cancer, her family announced. Look back at what she shared about her health journey.