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 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 was starting to become a regular presence on our TV screens before her death at age 33. Mack got her start in short films and small TV roles before joining bigger productions like The Walking Dead, 9-1-1 and Chicago Med. She was outspoken about how playing Addy on the post-apocalyptic show introduced her to an online fanbase.