Walking Dead Actress Kelley Mack Dies Unexpectedly at 33

Kelley Mack, known for her role as Addy in season nine of The Walking Dead, passed away unexpectedly at age 33 due to diffuse midline glioma, a cancer of the central nervous system that caused a tumor on her spinal cord. Despite being diagnosed in February and undergoing treatment, she experienced a sudden relapse just weeks before her death on August 2, 2025, after a period of apparent recovery. Her representatives and family expressed surprise at the rapid decline, noting she had been auditioning for roles as recently as June and only took a break in early July. Mack died peacefully surrounded by family, and her sister shared an emotional message highlighting her bravery and love for those close to her. The actress had also appeared in shows like Chicago Med and 9-1-1 and was active in voiceover work shortly before her passing. A life celebration is planned for August 16 in Ohio to honor her memory.