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.

Kelley Mack’s death shocked her loved ones. Mack’s rep told TMZ Thursday that the “Walking Dead” star’s passing at age 33 was a “total” surprise. Mack, according to her rep, was auditioning for roles earlier this summer after she underwent cancer treatment in February and experienced a “nice recovery.”