Kelley Mack’s Cause of Death Revealed After Emotional Instagram Post Says Walking Dead Star Died at 33

Actor Kelley Mack, who played Addy in Season 9 of the popular zombie series The Walking Dead, has died. She was 33 years old.

Mack was diagnosed with diffuse midline glioma, a rare form of cancer, after complaining of persistent lower back pain. In January, she announced that an “abnormal mass” was found on her spine, which led to her losing the use of both her legs.

After undergoing treatment in her hometown of Cincinnati for several months, the actor’s family shared that Mack died on August 2.

“It is with indelible sadness that we are announcing the passing of our dear Kelley. Such a bright, fervent light has transitioned to the beyond,” her family wrote on her Instagram page on Wednesday. “Kelley passed peacefully on Saturday evening with her loving mother Kristen and steadfast aunt Karen present.”

View full post on Instagram

“She will be missed by so many to depths that words cannot express,” the statement read. A celebration of life is scheduled for the star in Ohio on August 16.

Many were quick to take to the comments to express their condolences for Mack’s passing.

American actor Alanna Masterson, who appeared alongside Mack in The Walking Dead, wrote: “What an incredible human. So proud to have fought alongside her in our final episode together.”

Meanwhile, Gustavo Gomez, who played Marco in the hit series, added: “This is heartbreaking. I feel so lucky that our paths crossed. Your bright light will always shine on.”

Elsewhere, director Michael E. Satrazemis, who worked alongside Mack, said: “I was lucky enough to create with Kelley on The Walking Dead. A bright light on every level. All my love to those who love her.”

Mack is survived by her mother and father, Kristen and Lindsay Klebenow; her sister, Kathryn; her brother, Parker; and grandmother and grandfather Lois and Larry Klebenow.

“As her sister, I want you all to know how brave that tough SOB was, especially when she decided to make the leap to be reunited with God,” Kathryn wrote. “I’m so f––ing proud of her.”

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Kimberley Bond

Multiplatform Writer

Kimberley Bond is a Multiplatform Writer for Harper’s Bazaar, focusing on the arts, culture, careers and lifestyle. She previously worked as a Features Writer for Cosmopolitan UK, and has bylines at The Telegraph, The Independent and British Vogue among countless others.