'9-1-1' Alum Kelley Mack's Death Was 'Total' Surprise After Treatment

Actress Kelley Mack‘s death came as a shock to those in her inner circle after she underwent treatment during her glioma battle.

A rep for the Walking Dead alum told TMZ that her death was a “total” surprise, noting that Mack was auditioning for projects earlier in the summer. By July, Mack took a break from the audition circuit, but the rep said “no one expected” the news of her death. (A family source told the outlet that Mack made a “nice recovery” following her treatment earlier this year.)

Mack’s sister Kathryn announced via Instagram on Tuesday, August 5, that she died “peacefully” at age 33 days prior.

“It is with indelible sadness that we are announcing the passing of our dear Kelley,” her statement read. “Such a bright, fervent light has transitioned to the beyond, where we all eventually must go. … She will be missed by so many to depths that words cannot express.”

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Kathryn praised her sister’s strength throughout her health battle and thanked those who supported the actress along the way. “She would want you all to know how much she loves you,” she wrote. “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.”

Mack was best known for playing Addy on The Walking Dead, joining the cast in season 9. She also portrayed Penelope Jacobs on season 8 of Chicago Med and had a cameo role on 9-1-1. Before her death, Mack worked on a sci-fi film titled Universal.

Mack revealed in January that she was diagnosed with glioma, an “extremely rare” cancer, after experiencing “persistent lower back pain” and other symptoms in the fall. At the time, Mack told fans that she “lost the use of my right leg and most of my left leg” following a biopsy surgery on her spinal cord.

“I am very grateful to have such a supportive and loving family and boyfriend, who have been with me every second of this process,” she wrote via Instagram. “It has been a very emotional and challenging time, truly testing my mental fortitude, faith, and physical strength. They are so positive and we have a sense of calm knowing that my healing is taking place and we will overcome. … I am determined and know that this will eventually be a short chapter in my long book. The positivity, love and prayers that are being sent my way already is overwhelming and I feel it all. Thank you so much .”

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Mack continued to keep her social media followers in the loop with updates on her health journey. In February, she was “feeling very positive overall,” giving a glimpse of herself in physical therapy. One month later, Mack revealed that she completed proton radiation treatment and was “adjusting” to a new routine while staying in Florida.

“Overall, this journey has not been easy, but things are getting better — improvements are tough to see when you’re in the thick of it. Thank you again and again for the support and prayers ,” she wrote in March.