Kelley Mack Cause of Death: The entertainment world was struck with profound sadness on August 5, 2025, when the news broke that Kelley Mack, a talented actress known for her role as Addy on The Walking Dead, passed away at the age of 33. Her death, caused by a battle with glioma of the central nervous system, has left fans, friends, and family mourning the loss of a vibrant soul who brought light to every project she touched. In this article, we’ll explore Kelley Mack’s life, her career, the illness that took her, and the legacy she leaves behind.
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A Rising Star in Hollywood
Kelley Mack, born Kelley Lynne Klebenow on July 10, 1992, in Cincinnati, Ohio, was a multifaceted talent whose passion for storytelling began at a young age. Growing up in various cities, including Wyoming, Ohio, and Hinsdale, Illinois, Kelley’s love for the arts was sparked by a mini video camera she received as a birthday gift. This small device ignited a creative fire that would define her career.
- Early Beginnings: Kelley started acting in commercials as a child, showcasing her natural charisma.
- Breakout Role: She gained recognition for her role as Chloe in The Elephant Garden (2008), earning an Acting Award from NYU’s Tisch School of the Arts.
- Education: She graduated from Hinsdale Central High School in 2010 and earned a bachelor’s degree in Cinematography from Chapman University’s Dodge College of Film in 2014.
Her role as Addy in Season 9 of The Walking Dead (2018–2019) brought her into the spotlight, where she portrayed a Hilltop Colony resident with depth and authenticity. Beyond The Walking Dead, Kelley appeared in shows like 9-1-1 and Chicago Med, and lent her voice to projects like Spider-Man: Into the Spider-Verse, where she was the voice match for Hailee Steinfeld’s Gwen Stacy.
The Battle with Glioma
Kelley’s life took a challenging turn in September 2024 when she was diagnosed with diffuse midline glioma, a rare and aggressive form of brain cancer affecting the central nervous system. According to the Cleveland Clinic, gliomas are tumors that form when glial cells, which support and protect neurons, grow uncontrollably. These tumors often develop in the brain or spinal cord and vary in aggressiveness.
Kelley shared her journey openly on social media, detailing the symptoms that led to her diagnosis:
- Initial Symptoms: Persistent lower back pain, initially thought to be a slipped disc, followed by neuropathic itching in her right thigh and severe leg and back pain.
- Diagnosis: Emergency MRIs on Thanksgiving Eve 2024 revealed an abnormal mass in her spinal cord, later identified as diffuse midline glioma.
- Impact: A biopsy surgery on her spinal cord resulted in the loss of mobility in her right leg and most of her left, requiring her to use a walker and wheelchair.
Despite these challenges, Kelley remained resilient, undergoing proton radiation treatment, which she completed in March 2025. She shared updates about her progress, expressing gratitude for the support of her loved ones and fans. Her courage in facing such a daunting illness was a testament to her strength.
A Life of Creativity and Passion
Kelley’s career was marked by versatility and a deep love for storytelling. Beyond acting, she was a producer, writer, and voice-over artist. Her work extended to commercials for brands like Dr Pepper, Dairy Queen, and Chick-fil-A, and she served as an executive producer on the upcoming film Universal (2025), in which she also starred. Her creative spirit shone through in every project, from horror films like Broadcast Signal Intrusion (2021) to the comedy-drama Delicate Arch (2024).
Kelley’s family and friends remember her not just for her professional achievements but for her vibrant personality. She was an accomplished college tennis player, loved hiking, pickleball, and playing the piano, and had a penchant for dark chocolate, bourbon, and country music. Her warmth and creativity left a lasting impact on those who knew her.
Tributes from Loved Ones and Colleagues
The announcement of Kelley’s passing, shared by her sister Kathryn on Instagram, touched the hearts of many. The post described Kelley as a “bright, fervent light” who passed peacefully on August 2, 2025, surrounded by her mother, Kristen, and aunt, Karen. The poignant mention of Kelley appearing to loved ones as butterflies added a heartfelt touch to the tribute, symbolizing her enduring presence.
Colleagues from The Walking Dead shared their grief:
- Michael E. Satrazemis, a filmmaker, wrote, “I was lucky enough to create with Kelley on TWD. A bright light on every level.”
- Gustavo Gomez, who played Marco, said, “This is heartbreaking. I feel so lucky that our paths crossed. Your bright light will always shine on.”
- Anthony Michael Lopez, who portrayed Oscar, expressed, “Kelley was such a sweet and happy soul… Rest easy Kelley.”
Fans echoed these sentiments on social media, with one writing, “Oh no. Loved her in Broadcast Signal Intrusion. Rest in Peace Kelley,” and another noting, “This is so sad and so young.”
A Legacy That Lives On
Kelley Mack’s legacy is one of courage, creativity, and connection. Her family has planned a remembrance ceremony in Glendale, Ohio, on August 16, 2025, and a celebration of life in Los Angeles for her friends and colleagues. Her final project, Universal, will be screened at the Portland Festival of Cinema, Animation and Technology and the Chain NYC Film Festival in August 2025, ensuring her work continues to inspire.
Kelley’s openness about her battle with glioma raised awareness about this rare cancer, and her story reminds us of the fragility of life and the importance of cherishing every moment. Her family emphasized her bravery, with Kathryn noting, “I’m so f–king proud of her” for her strength in facing her illness.
As we reflect on Kelley Mack’s life, we celebrate a woman who lived passionately, loved deeply, and left an indelible mark on the world. Her light may have transitioned, but it continues to shine through her work, her loved ones, and the butterflies that carry her spirit.