Kelley Mack, famous for her roles on "The Walking Dead" and "Chicago Med" has died of cancer at age 33. Her sister, Kathryn, announced Mack's passing Tuesday on Mack's Instagram page. Mack died Saturday according to the post.

At the time of her death, the Ohio-born actor had been actively promoting the independent sci-fi feature "Universal," in which she has a starring role.

A ctress and filmmaker Kelley Mack, who was best known for playing Addy in The Walking Dead, sadly passed away on August 2 in Cincinnati after a seven-month battle with a central-nervous-system glioma at the age of just 33. The news was shared in a post on her family’s CaringBridge page said she “passed peacefully, surrounded by love.”