The actress quietly faced a deeply personal journey in recent months, leaning on close family while keeping much of her struggle out of the spotlight.

Kelley Mack, a rising star known for her role as Addy in AMC’s *The Walking Dead*, has died at the age of 33 following an intense and public battle with a rare form of cancer.

The actress, who also made guest appearances in *Chicago Med* and *9-1-1*, passed away peacefully on Saturday, August 2, in her hometown of Cincinnati, Ohio. She was surrounded by family, including her mother Kristen and her aunt Karen, during her final moments.

Her death was confirmed by her sister, Kathryn Klebenow, through a heartfelt message posted on Mack’s Instagram page:

“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 that Kelley had already “come to many of her loved ones in the form of various butterflies,” a detail that resonated deeply with fans who had followed Mack’s health updates in recent months.

Kelley Mack, whose birth name was Kelley Lynne Klebenow, began acting as a child in commercials before breaking into film and television. Her first major film appearance came in *The Elephant Garden*, which earned a Student Visionary Award at the 2008 Tribeca Film Festival.

However, it was her portrayal of Addy, a Hilltop Colony resident in *The Walking Dead*, that introduced her to a broader audience.

Although originally scheduled to appear in only two episodes of the series, Mack ultimately remained for five, a turn of events she once described in a 2019 interview as “an unexpected blessing.”

In October 2024, Mack began experiencing persistent lower back pain. What initially seemed like a minor issue soon escalated.

The night before Thanksgiving, she visited the emergency room and underwent an MRI. The results revealed something far more serious: an abnormal mass on her spinal cord.

In January 2025, she was diagnosed with diffuse midline glioma, a rare and aggressive tumor that affects the brain and spinal cord. This form of glioma is most commonly seen in children and young adults and has a notoriously poor prognosis.

Following her diagnosis, Mack underwent a biopsy that tragically left her paralyzed in one leg and partially paralyzed in the other.

Determined to maintain her independence and spirit, she began using a walker and a wheelchair to move around and shared her rehabilitation journey on social media.

In March, she posted a video of herself during physical therapy, walking up stairs with the support of a railing. “Life has also had its ups and downs lately am I right,” she wrote with a touch of humor that typified her personality.

Mack used the health platform CaringBridge to document her battle, posting updates that were unflinchingly honest but always touched with hope.

Her writing was raw and reflective, and many followers described her words as a source of inspiration. She spoke openly about her fear, her faith, and the small joys that sustained her, such as visits from friends and the comfort of her family.

Her sister Kathryn later wrote on social media, “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—king proud of her.”

The post echoed the raw emotion that has since poured in from fans and colleagues alike.

Mack’s acting career, while cut short, included roles that showcased her versatility. In addition to her recurring role in *The Walking Dead*, she starred in several short films, some of which she also produced.

Her appearances on *Chicago Med* and *9-1-1* revealed her potential as a dramatic actress, and casting directors had reportedly begun to notice her range just before her diagnosis.

Though her time in the spotlight was brief, Mack left an enduring impression on both her colleagues and fans. Fellow actors from *The Walking Dead* shared tributes online, recalling her kindness on set and her commitment to her craft.

One former co-star wrote, “She lit up every scene she was in—not just with her talent, but with her warmth.”

Kelley is survived by her parents Kristen and Lindsay Klebenow, her sister Kathryn, brother Parker, and grandparents Lois and Larry Klebenow.

Her funeral is scheduled for August 16 in Glendale, Ohio, and her family has requested that mourners wear bright colors rather than black to honor her love of life, art, and nature.

Though her journey was tragically short, Kelley Mack lived it with courage, purpose, and passion. Her story, though marked by pain, also served as a reminder of the strength found in vulnerability and the power of sharing one’s truth.

For those left behind, she has become more than just an actress on a screen—she is a symbol of resilience, love, and the fleeting beauty of a butterfly’s flight.