Despite her immense courage and determination, the illness ultimately took its toll. She passed away peacefully, surrounded by loved ones.
The actress in question was Kelley Mack, best known for her role as Addy in season nine of The Walking Dead. Born Kelley Lynne Klebenow, she died on August 2 after a brave fight with diffuse midline glioma — a fast-growing cancer affecting the central nervous system. In a post on her official Instagram page, her family described her as a “bright, fervent light” and shared that she had already “come to many of her loved ones in the form of various butterflies.”
Kelley first began experiencing symptoms in September 2024, initially attributing her lower back pain to a slipped disc. But her condition rapidly deteriorated, with pain spreading and mobility worsening. By Thanksgiving, doctors discovered an abnormal mass on her spinal cord. A biopsy confirmed the devastating diagnosis, and complications from the procedure left her partially paralyzed.
In spite of her circumstances, Kelley remained incredibly resilient. In a post shared in January, she expressed gratitude to her family for their support and remained optimistic, writing: “I am determined and know that this will eventually be a short chapter in my long book.”
Throughout her career, Kelley appeared in numerous TV shows, including 9-1-1, Chicago Med, and Schooled. She also took on roles in several short films and starred in the indie feature Universal, which was released earlier this year.
A memorial service will be held in Glendale, Ohio, on August 16, with a separate tribute planned for her friends and colleagues in Los Angeles. Her family says Kelley would want everyone to know how much she loved them — and how proud she was to live life boldly, even in the face of unimaginable hardship.