Overview

• Mack died on August 2 in Cincinnati, passing peacefully after battling a central nervous system glioma, according to an August 5 Instagram statement by her sister, Kathryn Klebenow.
• Best known for her role as Addy in season 9 of The Walking Dead, she also portrayed Penelope Jacobs on Chicago Med and guest-starred on 9-1-1, compiling 35 acting and five producer credits.
• Beyond on-screen work, she provided the voice match for Gwen Stacy in the Oscar-winning Spider-Man: Into the Spider-Verse and executive produced the film Universal, released June 21.
• After publicly announcing her diagnosis in September 2024, she documented her intensive treatments and therapy, raising awareness of diffuse midline glioma and earning admiration for her fortitude.
• Friends and colleagues—including co-star Alanna Masterson—have shared heartfelt remembrances ahead of a memorial service on August 16 at the Glendale Lyceum in Ohio.