Article continues below advertisementKelley Mack, known for her roles on hit franchises like The Walking Dead and 9-1-1, shocked fans when she died at the age of 33. Fans are curious to know the young actress' cause of death and the health issues she suffered leading to her passing, including a battle with glioma, a rare form of cancer.Article continues below advertisementWhat Was Kelley Mack's Cause of Death?Source: MEGAKelley Mack died on August 2, 2025.Mack died on August 2, succumbing to her battle with glioma of the central nervous system.