Actress Kelley Mack, best known for her role as Addy on the hit AMC series The Walking Dead, died on August 2, 2025, at the age of 33. She passed away peacefully in her hometown of Cincinnati, Ohio, surrounded by her mother and aunt, following a battle with a rare and aggressive brain tumor. Her death was confirmed by her family via CaringBridge and later reported by major news outlets.
Born Kelley Lynne Klebenow on July 10, 1992, Mack built a career that spanned more than a decade, accumulating 35 acting credits and 5 producer credits. She appeared in films, national commercials, and television series including Chicago Med and 9-1-1. Yet it was her portrayal of the scrappy survivor Addy in Season 9 of The Walking Dead that earned her the widest recognition.
Her diagnosis of diffuse midline glioma, a rare form of astrocytoma, was disclosed in a January 2025 Instagram post. The disease and its treatment eventually took a severe toll on her mobility, but Mack continued to work creatively, co-writing scripts and producing projects alongside family members.
Who Was Kelley Mack?
Full name: Kelley Lynne Klebenow • Born: July 10, 1992, Cincinnati, Ohio • Died: August 2, 2025 (age 33) • Known for: Playing Addy on The Walking Dead (Season 9)
- Her cause of death was diffuse midline glioma, a rare astrocytoma-type brain tumor.
- Her most prominent acting credit was Addy on The Walking Dead in 2018.
- She worked as an actress, producer, voiceover artist, and writer.
- Her family confirmed the news, which was covered by The New York Times and other outlets.
- No verified evidence exists that she appeared on the TV show 911 or Chicago Med; those queries may stem from confusion with other actresses.
- She earned a degree in cinematography from Chapman University in 2014.
- She was the oldest of three children; her brother is actor Parker Mack.
| Detail | Information |
|---|---|
| Birth name | Kelley Lynne Klebenow |
| Date of birth | July 10, 1992 |
| Place of birth | Cincinnati, Ohio, USA |
| Date of death | August 2, 2025 |
| Age at death | 33 |
| Cause of death | Diffuse midline glioma (astrocytoma) |
| Profession | Actress, producer, voice-over artist |
| Notable role | Addy on The Walking Dead (Season 9) |
| Education | Chapman University, Dodge College of Film and Media Arts (BA in Cinematography, 2014) |
| @itskelleymack | |
| Family | Parents Kristen and Lindsay Klebenow; siblings Kathryn and Parker Mack |
What Was Kelley Mack’s Cause of Death?
Kelley Mack died from diffuse midline glioma, a rare subtype of glial tumors that affects the central nervous system. In a January 2025 Instagram post, she described the diagnosis as an “extremely rare type of astrocytoma cancer.” The disease led to a biopsy surgery on her spinal cord, after which she lost the use of her right leg and most of her left leg, requiring a walker and wheelchair.
How old was she when she died?
She was 33 years old, having celebrated her birthday just weeks before passing.
Was there a 911 call related to her death?
No public 911 call transcripts or police reports have been released. Searches for “Kelley Mack 911” likely result from online curiosity rather than any confirmed incident. Mack died peacefully at home with family present, according to her family’s statements.
The specific diagnosis was diffuse midline glioma, not simply “astrocytoma glioma.” While it is a type of astrocytoma, the precise medical term reflects the tumor’s location and cell type. The National Cancer Institute provides information on this rare brain tumor category.
What Role Did Kelley Mack Play on The Walking Dead?
Mack played Addy, a member of the Hilltop community, in Season 9 of The Walking Dead. Her character appeared in several episodes during the season’s first half and was killed off. The role brought her to the attention of a global audience and remains her most frequently cited credit.
Did Kelley Mack appear on 911 or Chicago Med?
Sources such as ABC News and Variety list her as having appeared on both 9-1-1 (the FOX emergency drama) and Chicago Med (as Penelope Jacobs in Season 8). However, some fans have questioned these credits; the roles appear in her filmography but detailed episode confirmations are sparse. No reputable source contradicts the listings.
What other TV shows and movies was she in?
- Broadcast Signal Intrusion – feature film, role of Alice
- Delicate Arch – feature film, role of Wild
- Universal – upcoming film, role of Ricky
- The Elephant Garden – early lead role, earned an accolade from Tisch School of the Arts
- Commercials for Dr. Pepper, Ross Stores, Dairy Queen, and Chick-fil-A
Where can I find Kelley Mack’s last photo?
Multiple images circulate online. The most likely authentic recent photograph would be her final Instagram post on her verified account (@itskelleymack). Without direct confirmation from her family, viewers should treat other images with caution.
Kelley Mack also co-wrote full-length scripts with Kristen Klebenow, including “On The Black,” a 1950s college baseball story inspired by her maternal grandparents. She served as a producer on several projects alongside family members.
What Was the Timeline of Kelley Mack’s Life and Career?
- July 10, 1992 – Born Kelley Lynne Klebenow in Cincinnati, Ohio.
- Early 2010s – Began acting, appearing in short films and guest roles; landed national commercials.
- 2014 – Graduated from Chapman University with a BA in Cinematography.
- 2018 – Cast as Addy on The Walking Dead (Season 9).
- 2019 – Addy killed off; Mack continues acting in film and television.
- 2020–2025 – Battled diffuse midline glioma; continued voice work and writing.
- August 2, 2025 – Died at age 33 in Cincinnati.
- August 6, 2025 – Family confirms death; The New York Times publishes obituary.
What Is Known and What Remains Unclear About Kelley Mack’s Death?
- Died on August 2, 2025 – confirmed by family and news reports.
- Cause of death: diffuse midline glioma – confirmed by NYT and family statement.
- Played Addy on The Walking Dead – confirmed by IMDb and Wikipedia.
- Death was peaceful, at home, with mother and aunt present.
- Whether she appeared on 911 or Chicago Med – no verified credit found; may be mistaken identity.
- Whether a 911 call was made at time of death – unverified; no reputable source mentions one.
- Authenticity of “last photo” circulating online – should be confirmed via family or official accounts.
Why Does Kelley Mack’s Death Matter?
Mack’s passing at 33 from a rare brain tumor brought public attention to diffuse midline glioma, a condition that primarily affects young people. Her role on The Walking Dead gave her a lasting footprint in pop culture. The limited public information about her illness and final days has prompted online speculation, but no evidence supports rumours of a 911 call or disputed casting. Her death underscores the importance of brain cancer awareness and research.
What Are the Key Sources and Tributes for Kelley Mack?
The most authoritative accounts come from The New York Times obituary and the family’s statement shared via CaringBridge. Her Wikipedia entry provides a structured biography, and IMDb lists her full filmography. Former co-stars paid tribute online, including Gustavo Gomez and Anthony Michael Lopez.
“Kelley Mack, who was best known for her role as Addy on the hit TV series ‘The Walking Dead,’ died in Cincinnati last weekend, her family said.”
— The New York Times, August 6, 2025
“Kelley Lynne Klebenow (July 10, 1992 – August 2, 2025), known professionally as Kelley Mack, was an American actress.”
— Wikipedia
“She played Addy in season 9 of The Walking Dead.”
— Wikipedia
What Is the Lasting Legacy of Kelley Mack?
Kelley Mack leaves behind a body of work that spans television, film, and commercial work. Her most recognised role as Addy introduced her to millions. Off-screen, she co-wrote scripts and produced films with family. Her courage in sharing her diagnosis publicly helped raise awareness about rare brain tumors. For more on actors who faced similar battles, see the article on Olivia Hussey – Cause of Death, Age and Lasting Legacy and the Brienne Tarth – Complete Guide to Game of Thrones Character.
Frequently Asked Questions
Was Kelley Mack on the TV show 911?
There is no verified evidence that Kelley Mack appeared on the TV show 911. This may be a confusion with another actress.
Did Kelley Mack play a role on Chicago Med?
No credible source lists Kelley Mack in the cast of Chicago Med. It might be a case of mistaken identity or a minor uncredited role that has not been confirmed.
What was Kelley Mack’s last photo?
Multiple photos have been shared online. The most likely authentic last photo would be her final Instagram post. However, without official confirmation from family, verification through her official account is recommended.
Was there a 911 call placed when Kelley Mack died?
No public 911 call transcripts or reports have been released. This search query likely originates from curiosity rather than any confirmed event.
Where was Kelley Mack born?
She was born in Cincinnati, Ohio, on July 10, 1992.
What did Kelley Mack study in college?
She earned a bachelor’s degree in cinematography from Chapman University’s Dodge College of Film and Media Arts in 2014.
Who are Kelley Mack’s siblings?
She was the oldest of three children: sister Kathryn and brother Parker Mack, who is also an actor.
James Sutton is Senior Reporter at ShowbizUK.co.uk, covering breaking showbiz and entertainment stories. He works under Editor-in-Chief Victoria Winslow and Managing Editor Oliver Bennett, following the newsroom standards for sourcing, verification and fact-checking set out in our editorial policies.