Chicago Med star Kelley Mack passed away on August 2, 2025, as confirmed by a statement shared on her Instagram account by her sister on August 5. She had just turned 33 in July.Kelley Mack portrayed Penelope Jacobs in Chicago Med in 2022, marking one of the most notable roles of her career. Besides being an actress, Mack also had voice-over and producing credits.The social media post on her account pointed to the link to her CaringBridge profile, which featured the formal announcement of her passing. Per the statement, the actress "passed away peacefully" in her hometown of Cincinnati, surrounded by the presence and support of her mother, Kristen, and her aunt, Karen.Kelley's sister announces her passing (Image via Instagram/@itskelleymack)The actress died after battling glioma of the nervous system.In January 2025, Kelley Mack mentioned via an Instagram post how she was diagnosed with diffuse midline glioma after getting an MRI after experiencing persistent pain in her lower back and neuropathic itching. She lost the use of her right leg after a biopsy surgery on her left leg.According to her last health update shared on Instagram in March, she had finished her proton radiation treatment.Kelley Mack guest-starred in Chicago Med season 8 as Penelope JacobsWhile the ongoing series Chicago Med has an overarching storyline, it also follows a 'case-of-the-week' format, and Kelley Mack was one of the guest stars featured in one of the procedural drama's cases. In Chicago Med season 8 episode 6, titled Mama Said There Would Be Days Like This, Mack appeared as Penelope Jacobs.She was a new single mother who arrived in distress with her baby, Edison, fearing that she would hurt him. Penelope had some violent fantasies about throwing her son against the wall when he was crying out loud, and feared that it would happen in real life. Whenever the baby cried, she felt like it was a drill in her head, and she did not feel like herself. View this post on Instagram Instagram PostWhile assessing Penelope's situation, Dr. Charles and Dr. Choi suspected that she was experiencing postpartum depression. Penelope turned out to have Bell's Palsy, making her unable to deal with a crying baby.More about Kelley Mack and her other acting creditsBorn in Cincinnati, Ohio, Kelley Mack grew up with her two younger siblings while moving around different cities in Ohio, Missouri, Connecticut, North Carolina, and Illinois. She had a bachelor's degree in Cinematography from Dodge College of Film at Chapman University. She then moved to Los Angeles to pursue a career in film.Shortly after she graduated from college, she got a guest-starring role in the crime series Unusual Suspects. That same year, she appeared in another show, Grayson: Earth One, and did two short films. View this post on Instagram Instagram PostWhile she mostly featured in short film projects throughout her career, Mack was also in movies such as Long Distance Trip, Mr. Manhattan, Shot in the Dark, and Delicate Arch. Outside of Chicago Med, she guest-starred in 9-1-1 and The Walking Dead. Her last acting project was Universal, a comedy-drama written and directed by Stephen Portland.There will be an upcoming life celebration dedicated to the late Kelley Mack on August 16 in Ohio.