The Walking Dead writer Scott M. Gimple is paying tribute to Kelley Mack after the actress’ death at 33 years old.
“Sad news about a massively talented member of the TWD family,” Gimple, 54, wrote via X on Wednesday, August 6. “We’re grateful we got to work with Kelley Mack and share her magic with the world.”
Mack was best known for her role as Addy in season 9 of the post-apocalyptic horror drama.
Mack’s sister, Kathryn, confirmed her death via a post on the 9-1-1 alum’s Instagram page on Tuesday, August 5.
Who Is ‘9-1-1’ Actress Kelley Mack? What to Know After Her Death at Age 33
“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, where we all eventually must go,” she wrote.
The post continued, “Kelley passed peacefully on Saturday evening with her loving mother Kristen and steadfast aunt Karen present. Kelley has already come to many of her loved ones in the form of various butterflies 
. She will be missed by so many to depths that words cannot express.”
Kathryn concluded, “Kelley’s Caringbridge link in her bio includes the 2-page formal announcement with information on her upcoming life celebration in Ohio on August 16th. She would want you all to know how much she loves you. And 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. I’m so f***ing proud of her.”
Eight months before her death, Mack announced that she had been diagnosed with diffuse midline glioma (DMG), a rare form of cancer that causes tumors in the brain and spinal cord.
“In September, I moved into a new apartment with my boyfriend, Logan. For a month after that, I had persistent lower back pain and thought I slipped a disc. A few weeks later, I had neuropathic itching in my right quad,” she wrote via Instagram in January. “And then, the shooting pains in my legs and back began, which resulted in me having to sleep in a recliner for a month because laying down was too painful. On Thanksgiving Eve, I had emergency MRIs done at the hospital, which revealed an abnormal mass in my spinal cord.”
Mack explained that she had a biopsy surgery done on her spinal cord, which left her unable to use her right leg “and most of my left leg.”
“So I now get around with a walker and a wheelchair,” she added.
“I am very grateful to have such a supportive and loving family and boyfriend, who have been with me every second of this process. It has been a very emotional and challenging time, truly testing my mental fortitude, faith, and physical strength,” she continued. “They are so positive and we have a sense of calm knowing that my healing is taking place and we will overcome. This experience has brought me closer to God, and I am leaning on him and trust his plan for me.”
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Mack told fans that her acting career would be “somewhat paused” as she underwent radiation treatment in Cincinnati, “where my family is located.”
Over the next few months, Mack continued to share updates with fans, including videos of her learning to walk again.
A rep for Mack told TMZ that her death came as a “total” surprise, as she had been auditioning for projects earlier in the summer. Though she took a break from auditions by July, her rep said “no one expected” the news of her death.
Meanwhile, a family source told the outlet that Mack had made a “nice recovery” following her treatment earlier this year.
