The Walking Dead actress Kelley Mack has died at the age of 33.

Mack (real name: Kelley Lynne Klebenow) passed away on August 2 following a battle with cancer, her family announced on Instagram on Tuesday.

Mack had been stricken with glioma of the central nervous system, according to a statement her family shared on CaringBridge.

The rising star’s most prominent role during her lifetime was as Addy on The Walking Dead’s ninth season, which aired from 2018 to 2019.

Mack’s family noted that she would be honored at a celebration of life ceremony in Glendale, Ohio, on August 16, and a later memorial is planned for her friends and colleagues located around Los Angeles.

‘It is with indelible sadness that we are announcing the passing of our dear Kelley,’ her family wrote in a post shared to her Instagram account. ‘Such a bright, fervent light has transitioned to the beyond, where we all eventually must go.

The Walking Dead actress Kelley Mack has died at the age of 33. Mack passed away on August 2 following a battle with cancer, her family announced on Instagram on Tuesday

Mack (R) scored her most prominent role during her lifetime as Addy on The Walking Dead’s ninth season, which aired from 2018 to 2019; pictured with (L–R) Jackson Pace and Joe Ando-Hirsch

‘It is with indelible sadness that we are announcing the passing of our dear Kelley,’ her family wrote in a post shared to her Instagram account. ‘Such a bright, fervent light has transitioned to the beyond, where we all eventually must go’; pictured in 2021 in Chicago

‘Kelley passed peacefully on Saturday evening with her loving mother Kristen and steadfast aunt Karen present,’ they continued. ‘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.’

The statement concluded with a reminder that Mack ‘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.’

In January, Mack revealed on Instagram that she had first noticed symptoms of what was later diagnosed as a rare form of cancer in September 2024.

Alongside a photo of her beaming and flashing a thumbs up from a hospital bed, the actress wrote that she had suffered from ‘persistent lower back pain,’ which she assumed was from a ‘slipped disc.’ 

But after a few weeks the back pain was accompanied by itching caused by nerve pain in the front of her right thigh, and soon Mack said she was suffering from debilitating shooting pains in her legs and back that forced her to ‘sleep in a recliner for a month because laying down was too painful.’

She wrote that an emergency MRI conducted the day before Thanksgiving revealed an ‘abnormal mass’ on her spinal cord.

Mack said she was ultimately diagnosed with diffuse midline glioma, a rare form of cancer that begins as tumors in the brain or spine, according to the National Cancer Institute.

A statement posted to Mack’s Instagram page and penned by her sister said she died on Saturday with her ‘mother Kristen and steadfast aunt Karen present’; seen in October 2021 in Chicago

In January, Mack revealed on Instagram that she had first noticed symptoms of what was later diagnosed as a rare form of cancer in September 2024; pictured in October 2021 in LA

The actress shared a photo of herself in a hospital bed and recounted how her shooting back and leg pain forced her to ‘sleep in a recliner for a month because laying down was too painful’

The diagnosis is particularly devastating, as diffuse midline glioma are fast growing.

Mack added that even the steps to properly diagnose her cancer had ravaged her body and left her forced to use a wheelchair after the biopsy surgery on her spinal cord robbed her of total function in her right left and left her with only partial use of her left leg.

Mack thanked her family for their support and shared her hopes that coming forward about her illness could help others in similar situations. 

She wrote that she planned to have radiation treatments in Cincinnati to be close to her family. 

Mack remained defiant in the heartbreaking conclusion to her diagnosis post. 

‘I am determined and know that this will eventually be a short chapter in my long book,’ she wrote. ‘The positivity, love and prayers that are being sent my way already is overwhelming and I feel it all. Thank you so much ❤️❤️.’ 

Mack’s five-episode run on The Walking Dead was her most prominent role to date, but she had numerous parts in short films and TV shows going back to 2015. 

She also had guest roles on 9-1-1, Schooled and Chicago Med. Her final role was a lead part in the low-budget independent film Universal, which was released earlier this year, according to her IMDb page. 

Mack also had guest roles on 9-1-1, Schooled and Chicago Med. She will be honored with a celebration of life ceremony in Glendale, Ohio, on August 16; pictured in October 2021 in LA

Mack was born in Cincinnati and moved around during her childhood, with stints in Missouri, Connecticut, North Carolina and Illinois. 

She studied cinematography at Chapman University’s Dodge College of Film and worked around the LA area for more than a decade. 

She also worked behind the scenes in the film and television industry as an occasional producer, as well as doing voice acting work, including recording for Spider-Man: Into The Spider-Verse. 

Mack is survived by her mother Kristen and father Lindsay, as well as her sister Kathryn, brother Parker, her paternal grandparents and her boyfriend, Logan Lanier.