The One Chicago universe—composed of Chicago Fire, Chicago P.D., and Chicago Med—has built a legacy not just through high-stakes emergencies, thrilling action, and emotional cliffhangers, but also through the unforgettable characters that fans have grown to love over the years. So when those characters depart—whether tragically, mysteriously, or quietly—it leaves a lasting mark. Some exits have been sudden and shocking, while others came with a slow burn of inevitability. No matter how they leave, the pain remains the same. These are the characters who anchored their respective shows, formed deep bonds with others, and left holes in the hearts of fans that still haven’t quite healed.
First on the list is Alvin Olinsky from Chicago P.D.. A fan-favorite detective with a complicated past, Olinsky was the heart and soul of Voight’s unit. His death—stabbed in prison after being framed—was a gut punch that left both characters and fans in mourning. The fact that his demise came as a result of his loyalty to Voight made it even more tragic. While his return seems impossible in a literal sense, fans still cling to flashbacks and emotional mentions. Olinsky’s presence lingers in the DNA of the show.
Next is Leslie Shay from Chicago Fire. Shay’s quirky charm, her deep friendship with Dawson, and her unwavering bravery made her an early standout. Her death, caused by a collapsing beam during a fire call, remains one of the most shocking moments in the show’s history. The grief that followed—both on and off screen—was palpable. She’s made brief returns through dreams and memories, but a full return isn’t likely. Still, fans can’t help but wonder what Firehouse 51 would be like if she had stayed.
Erin Lindsay’s departure from Chicago P.D. was a quiet storm. After four seasons, she moved to New York to join the FBI. But the exit felt abrupt, especially given her deep bond with Voight and her evolving relationship with Halstead. Sophia Bush’s real-life decision to leave the show added complexity to her departure, especially with the backstage revelations that came later. The storyline left the door open for a return, but whether it will ever happen remains uncertain.
One of the most bittersweet exits came from Chicago Fire when Matt Casey left in Season 10. His reason was noble—moving to Oregon to care for his late best friend’s children—but it meant saying goodbye to one of the core pillars of Firehouse 51. His departure wasn’t a death, which gave fans hope. And sure enough, Casey has made some guest appearances since. While not a full-time return (yet), his storyline feels like it could be revisited at any moment.
Over on Chicago Med, Natalie Manning’s departure was both frustrating and heartbreaking. Fired for stealing medication to help her ailing mother, Natalie’s exit came after several seasons of ethical struggles and personal dilemmas. Her actions, while understandable, were unforgivable in the hospital’s eyes. Fans were divided, but many felt her story wasn’t over. Could she come back? Absolutely. The character’s goodbye wasn’t permanent—just painful.
Jay Halstead’s sudden exit from Chicago P.D. stunned viewers. After marrying Hailey Upton and being one of the most morally grounded characters in the unit, his decision to leave for a task force mission in Bolivia came out of nowhere. The exit felt rushed and poorly explained, leaving fans unsatisfied. Jesse Lee Soffer, who played Halstead, has since directed episodes, and rumors about a potential return continue to swirl. The character is still alive—and that means there’s still hope.
April Sexton’s departure from Chicago Med was understated. She chose to leave in order to pursue her nurse practitioner degree. It made sense within her character arc, but fans were sad to see her go, especially after her ups and downs with Ethan. Her return in Season 8 for a brief arc reignited interest in her character. April’s exit never felt final, and now we know for sure—she’s still part of the One Chicago world.
Antonio Dawson, one of the few characters who moved between Chicago Fire and Chicago P.D., had one of the most chaotic exits. After struggling with painkiller addiction and being caught in a scandal, he checked into rehab and left the force. His departure was tied to real-life controversies, and the lack of closure left fans dissatisfied. While a return isn’t impossible, it would require delicate storytelling and perhaps some behind-the-scenes healing.
Emily Foster’s short-lived presence on Chicago Fire brought a fresh dynamic to the paramedic team. Her decision to leave Firehouse 51 to return to medical school was sudden and unexplored. There was no farewell episode, no dramatic goodbye—just a line of dialogue and she was gone. It’s rare for a character to vanish so quietly, and fans still want answers. Technically, she could return, but there’s no word on any plans.
Finally, Peter Mills, one of Chicago Fire’s original cast members, had perhaps the most underrated departure. After years of service and personal growth, he left to run a family restaurant in North Carolina. His character deserved more—more drama, more farewell, more follow-up. Still, Charlie Barnett has expressed willingness to return, and with all the recent crossovers and cameos, there’s always a chance we could see Mills walk back through the firehouse doors.
These ten characters represent more than just faces on a screen. They embody the emotional core of One Chicago. Their departures were not just plot points—they were major turning points that altered the tone and trajectory of their respective shows. Some left in body but not in spirit, others were given brutal endings, and a few simply walked away, leaving unfinished business behind.
