FILE - Actress Kelley Mack on the red carpet for "Broadcast Signal Intrusion" during the 57th Chicago International Film Festival at the AMC River East Theater on October 14, 2021 in Chicago, Illinois. (Photo by Barry Brecheisen/Getty Images)
Kelley Mack, the actress who played "Addy" in season 9 of "The Walking Dead," has died. She was 33 years old.
Her family announced her death on Mack’s Instagram page. Her real name was Kelley Klebenow.
Kelley Mack’s death
Mack died of an aggressive glioma, or tumor, that attacked her central nervous system, her family said.
What they're saying:
"It is with indelible sadness that we are announcing the passing of our dear Kelley," her sister posted on Mack’s Instagram page. "Such a bright, fervent light has transitioned to the beyond, where we all eventually must go. 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."
Mack shared her struggles with the tumor on Instagram, posting in January about how the tumor was diagnosed. She said it started with persistent lower back pain, neuropathic itching, and shooting pains in her legs. Her diagnosis was diffuse midline glioma, an extremely rare type of astrocytoma cancer.
She said she lost the use of her right leg and most of her left leg during biopsy on her spinal cord.
Kelley Mack’s life and career
The backstory:
Kelley Mack was born in Cincinnati, Ohio, and lived in several Ohio towns, as well as in Connecticut, Missouri, North Carolina and Illinois, according to her obituary on the website Caring Bridge.
She earned her bachelor’s degree in cinematography from the Dodge College of Film at Chapman University in Orange, California.
RELATED: Celebrity deaths of 2025: Who we've lost this year
Her family said Mack had 35 acting roles and was a producer on five productions. Those include "Addy" in season 9 of "The Walking Dead," Penelope Jacobs is season 8 of "Chicago Med" and on FOX’s "9-1-1." Her movie roles include "Broadcast Signal Intrusion," "Delicate Arch" and the upcoming film "Universal."
"Kelley’s love for storytelling blossomed at a young age when she received a mini video camera as a birthday gift," her family said. "
She also did voice-over work and commercials, including in "Spider-Man: Into the Spider-Verse."
"Kelley was known for her warmth, creativity, and unwavering support for those around her," her family said. "She cherished time with family and friends, finding joy in collaboration and storytelling. Her infectious enthusiasm and dedication to her work inspired countless others in the industry and beyond."
What is diffuse midline glioma?
Dig deeper:
"Diffuse midline gliomas tumors are extremely aggressive, and are classified as grade IV tumors," according to the University of California San Francisco. "As the name suggests, the tumor cells tend to spread out and invade neighboring tissue. Often, diffuse midline gliomas will have grown throughout the brainstem."
The Source: This report includes information from Kelley Mack's Instagram page, Caring Bridge and the University of California San Francisco.