Kelley Mack's death at 33 is putting glioma under the spotlight. After news broke that The Walking Dead and 9-1-1 star had died on Saturday, August 2, fans were reminded that the actress was recently diagnosed with glioma of the central nervous system. "In September, I moved into a new apartment with my boyfriend, Logan. For a month after that, I had persistent lower back pain and thought I slipped a disc," Mack shared via Instagram in January. "A few weeks later, I had neuropathic itching in my right quad.