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Kelley Mack, known for her role as Addy in Season 9 of The Walking Dead, has passed away at just 33 years old following a battle with a rare and aggressive form of cancer.
Fight Against a Rare Cancer
Mack was diagnosed in September 2024 with diffuse midline glioma, a type of central nervous system tumor that affects the brain or spinal cord. Initially, she attributed persistent back pain and nerve-related symptoms to a slipped disc. An emergency MRI revealed the tumor—a diagnosis that proved devastating and ultimately fatal. The cancer’s prognosis is rarely favorable and notoriously hard to treat. (The Sun, The Times of India)
She passed away on August 2, 2025, in Cincinnati, Ohio, surrounded by her mother and aunt. Her family confirmed her death via Instagram on August 5, sharing that Mack transitioned peacefully and that she has already appeared to loved ones symbolically as butterflies—an emblem of her enduring light. (People.com)
A Career of Stories and Impact
Born Kelley Lynne Klebenow on July 10, 1992, Mack studied cinematography at Chapman University, graduating in 2014. She appeared in 35 acting roles and held five producer credits, participating in films and TV, including Broadcast Signal Intrusion, Delicate Arch, Chicago Med, and 9-1-1. On The Walking Dead, her character Addy was a recurring presence in Season 9. Her final role is credited in the upcoming film Universal. (EW.com)
Additionally, Kelley lent her voice to ads and projects, including voice‑matching Gwen Stacy in promotions for Spider-Man: Into the Spider‑Verse, as well as commercials for recognizable brands. (People.com)
Tributes and Remembrance
Mack is remembered by family and fans alike as a “bright, fervent light” whose warmth, creativity, and unwavering support left a mark on everyone she encountered. Her Instagram tribute described her as peaceful and spirited until the end. (EW.com)
A celebration of life and remembrance gathering will take place on August 16 in Ohio, with plans for a future memorial in Los Angeles, where she had lived and worked for 11 years. (The Sun)
Legacy
Kelley Mack’s career may have spanned just over a decade, but she left a lasting impression through captivating roles and her dedication to storytelling—both as an actress and a producer. She is survived by her parents, sister Kathryn, brother Parker (also an actor), grandparents, and boyfriend, whose grief is shared by many in the entertainment world. (EW.com)
🧭 Key Facts at a Glance
| Detail | Information |
|---|---|
| Date of Birth | July 10, 1992 |
| Date of Death | August 2, 2025 |
| Cause of Death | Difficult battle with diffuse midline glioma |
| Age | 33 |
| Notable Role | Addy, The Walking Dead (Season 9) |
| Other Credits | Chicago Med, 9‑1‑1, Broadcast Signal Intrusion, Delicate Arch, Universal |
| Voice Work | Gwen Stacy promotions in Spider‑Man: Into the Spider‑Verse, brand commercials |
🌟 Final Thoughts
Though her life and career were far too short, Kelley Mack’s light shone brightly—through her characters, her creative works, and the bonds she built along the way. Her memory will live on in the art she shared and the lives she touched.
