Kelley Mack, actress known for her role in The Walking Dead, died at the age of 33.

American actress Kelley Mack , known for her role as "Addy" in the hit zombie series "The Walking Dead," died at the age of 33 after battling a brain tumor, her sister confirmed on the artist's social media.

“It is with indelible sadness that we announce the passing of our beloved Kelley . Such a bright and fervent light has passed on to the afterlife, where we all must eventually go,” she wrote on Instagram.

Her sister also said the artist died "peacefully Saturday night with her loving mother, Kristen, and steadfast Aunt Karen present." "Kelley has already touched so many of her loved ones in the form of several butterflies. We will miss her so deeply that words cannot express her," she said.

On January 3, Mack also shared on social media the diagnosis she received after suffering from some pain in her lower back and legs: diffuse midline glioma (DMG) .

According to the prestigious Mayo Clinic , it is “a rare type of cancerous brain tumor” that, while most common in children between 5 and 10 years old, can also occur in adults.

It is “diffuse” because “the cancer cells have spread beyond the tumor and reached healthy brain tissue,” “midline” because “it is located in the middle of the central nervous system,” and it is called a glioma because “it developed from glial cells, which are auxiliary cells in the white matter of the brain,” the medical entity explains on its official website.

“She would want all of you 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 take the leap to join God. I am so proud of her,” her sister concluded.

Kelley Mack was born on July 10, 1992, in Cincinnati, Ohio, where her life will be celebrated on August 16.

She studied filmmaking at the Dodge College of Film and Media Arts at Chapman University before beginning her acting career in independent productions.

Her debut was in the short film “The Elephant Garden” and she then had supporting roles in productions such as “Chicago Med” and “9-1-1”, until she got the opportunity to shine in five episodes of the ninth season of “The Walking Dead” , between 2018 and 2019.

His character, who had survived a zombie apocalypse, was killed by the leader of a group known as “The Whisperers.”

On January 3, Mack revealed through her social media that she had a serious illness, the first symptoms of which she began experiencing in October of last year, with leg and back pain that forced her to sleep in a recliner.

Following this condition, he underwent an emergency MRI which revealed “an abnormal mass” in his spinal cord and was then informed of the diagnosis.

“Due to the spinal cord biopsy surgery, I've lost the use of my right leg and most of my left leg, so I now get around with a walker and a wheelchair,” he said at the time.

She added: "I'm determined, and I know this will finally be a short chapter in my long book. The positivity, love, and prayers you're sending me are already overwhelming, and I feel it all. Thank you so much."

Ten days later, at the start of her treatment, Mack posted another post describing her feelings on the first day of treatment. “I felt like I was filming an episode of my new TV show, set on a spaceship floating somewhere in our infinite galaxy,” she said.