The Walking Dead community is mourning the loss of actress Kelley Mack, who portrayed Adeline “Addy” on season 9 of the hit AMC series.
Mack, whose real name was Kelley Klebenow, died last Saturday at age 33 after a courageous seven-month battle with cancer.
She shared her diagnosis publicly on January 3 via Instagram, revealing that what began as "persistent lower back pain" ultimately led to the discovery of a rare and aggressive tumor.
In the post, she explained what happened when she visited the doctor for her back pain:
“A few weeks later, I had neuropathic itching in my right quad. 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.”
Emergency MRIs revealed an abnormal mass in her spinal cord. She was later diagnosed with diffuse midline glioma, a rare and typically incurable cancer affecting the brain, spinal cord, and eventually the nervous system.
You can view the post below:
Born on July 10, 1992, in Cincinnati, Ohio, Mack grew up in a close-knit family that moved often. She graduated from Hinsdale Central High School in Illinois and studied cinematography at Chapman University’s Dodge College of Film and Media Arts in California.
She is the older sister of actor Parker Mack, known for playing Finn Madell—a teen battling cancer—on Freeform’s Chasing Life.
On March 13, Mack shared an emotional update after completing proton radiation treatment. In a video posted to social media, she rang the hospital bell—symbolizing the end of treatment—with her boyfriend, actor Logan Lanier, by her side. She was seated in a wheelchair but smiling through tears.
You can watch the emotional moment here:
In addition to her acting work, Mack was a talented writer and producer. At the time of her death, she had just completed work on a film she starred in and executive produced, titled Universal, which has not yet been released.
She has also co-written screenplays with her mother, including On the Black, a 1950s baseball drama based on her maternal grandparents’ time at Ohio University.
Her family announced her passing on Tuesday, with her sister Kathryn sharing a heartfelt tribute:
“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.”
Kathryn added:
“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**king proud of her.”
You can view the family’s tribute here:
Mack got her start in commercials for major brands like Dr. Pepper, Chick-fil-A, and Dairy Queen before gradually building a versatile acting portfolio. She starred in several short films, including Simón, directed by Diego Vicentini, and she took on a chilling role in the horror thriller Broadcast Signal Intrusion, directed by Jacob Gentry and starring Glee’s Harry Shum Jr.
Her talents extended to voice work as well—she contributed to the Oscar-winning animated film Spider-Man: Into the Spider-Verse, serving as a vocal double for Hailee Steinfeld’s Gwen Stacy. Television audiences may also recognize her from guest roles as Penelope Jacobs on Chicago Med and appearances on 9-1-1.
Her breakout TV role came in 2018 when she joined The Walking Dead as Addy, a member of the Hilltop Colony for five episodes.
The teen character’s (spoiler alert) gruesome death—one of several victims decapitated by the villain Alpha—served as a major penultimate cliffhanger and shocked fans, reminiscent of the show’s infamous (again, spoiler alert) Negan-led massacre of Glenn and Abraham in Season 7.
The director, Michael Satrazemis of TWD and its subsequent spin-offs, commented on the family’s post:
“I was lucky enough to create with Kelley on TWD. A bright light on every level. All my love to those who love her.”
More stars of the series gave their condolences for the loss:
@alannamasterson/Instagram
@itsgustavogomez/Instagram
@anthonymichaellopez89/Instagram
And fans and colleagues posted on the actress’ social media:
@frankstalicious/Instagram
@chrisellealmeida/Instagram
@kaceyfifield/Instagram
@jschramer/Instagram
@ohno.alexvaughan/Instagram
@mattmangum2/Instagram
@caratastrophes/Instagram
@ghbales/Instagram
@nicolasnicolby/Instagram
@ajh.fitnesslifestyle/Instagram
@walkingdeadamc/Instagram
A remembrance ceremony will be held in her hometown of Glendale, Ohio, on August 16. A second memorial is being planned in Los Angeles for Mack’s friends and colleagues in the entertainment industry.
Kelley Mack is survived by her parents, Kristen and Lindsay Klebenow; her siblings, Kathryn and Parker; her grandparents; and her boyfriend, Logan Lanier.
You can read the family’s eulogy to Kelley Mack at her CaringBridge page.
@JamesTate121/X
