After over a decade on television, the interconnected One Chicago universe—comprising Chicago Fire, Chicago P.D., and Chicago Med—has seen a multitude of characters join and depart. While cast changes are inevitable in long-running procedurals, the year 2024 marked a particularly significant period of transition, with several pivotal figures exiting their respective series. These departures ranged from those that sparked little sentiment to those that resonated deeply with the audience, reshaping the landscape of their fictional worlds. Examining these shifts provides insight into the narrative evolution of the franchise and the lasting legacies of its characters.

One of the more straightforward departures from the One Chicago universe in 2024 was Dr. Zola Ahmad from Chicago Med. Introduced in Season 9 as a third-year emergency medicine resident at Gaffney Chicago Medical Center, Dr. Ahmad was placed on a probationary basis under Dr. Crockett Marcel. Her tenure was fraught with controversy from the outset; Zola had a history of being dismissed from previous positions due to impulsive medical decisions. This pattern continued at Gaffney, as she almost immediately made questionable choices, such as performing a neck hematoma decompression outside of an operating room and bringing a group of refugees with a suspected infectious disease directly to the Emergency Department on her very first day. Despite counsel from Marcel, her recklessness persisted throughout Season 9. Her professional journey culminated in her dismissal in Season 9, Episode 9, “Spin a Yard, Get Stuck in Your Own String,” merely seven episodes after her debut, following an incident where she jeopardized a living patient in a hurried attempt to deliver lungs for a transplant. While medical dramas often explore experimental approaches, Dr. Ahmad’s actions frequently veered into dangerous territory, earning her a reputation for being a challenging and disruptive presence among both colleagues and viewers. Her constant rule-breaking, despite occasionally stemming from good intentions, ultimately made her an unsustainable character within the established ethical framework of the medical drama. Her exit underscored the consequences of professional misconduct, reinforcing the high stakes inherent in the field of emergency medicine.

Chicago Fire also saw the swift departure of Derrick Gibson, a new firefighter on Truck 81 introduced in Season 12 as a replacement for Blake Gallo. Actor Rome Flynn’s casting initially generated excitement among fans, given his prior work in popular television series. Gibson arrived with a compelling, albeit tragic, backstory: he was a former amateur boxer who quit the sport after accidentally causing an opponent’s death in the ring, a trauma that subsequently led him to firefighting and also fostered a hidden struggle with medication addiction. Despite this rich potential, Gibson’s time at Firehouse 51 was notably brief, spanning only six episodes before his exit in Season 12, Episode 8, “All the Dark.” His departure occurred after Lieutenant Stella Kidd discovered him experiencing a severe panic attack, revealing the depth of his unresolved trauma. Gibson confessed his need to leave to address his personal struggles and addiction, stating, “I thought I pulled it together. I need to get out. I need to go.” With that, he left Firehouse 51, seeking help for his drug problem. The brevity of his arc meant viewers had little time to truly connect with the character, leaving many feeling that Chicago Fire missed an opportunity to delve deeper into his complex background and mental health challenges, themes the series often explores with great nuance. His quick exit highlighted the immediate and overwhelming nature of some personal battles, preventing a more integrated story arc for the character.

Another significant exit from Firehouse 51 was Blake Gallo, a firefighter on Truck 81, whose departure felt premature to many. Portrayed by Alberto Rosende, Gallo joined Chicago Fire in Season 8, stepping into the void left by the tragic death of Brian “Otis” Zvonecek. Gallo’s motivation for becoming a firefighter was deeply personal and resonant with the show’s themes: he had lost his entire family, including his parents and younger sister, in a house fire at the age of twelve and was saved by Firehouse 131. This foundational trauma fueled his dedication to the profession. Over his tenure, Gallo brought a dynamic energy to the team, often providing comedic relief and forming engaging relationships. His playful rivalry with paramedic Violet Miakmi, with whom he shared a history from the Fire Academy, evolved into a brief romantic relationship, adding layers to his character. He also dated other characters like Tracy Herrmann (Christopher Herrmann’s niece), Gianna Mackey, and Cara. Despite his compelling backstory and role in the firehouse family, Gallo often served more as a spirited sidekick rather than receiving the extensive heroic storylines given to figures like Kelly Severide or Matt Casey. His exit in the Season 12 premiere, “Barely Gone,” was abrupt, with Gallo revealing his decision to move to Detroit, Michigan, to live with his aunt, his last living relative, and continue his firefighting career there. While his departure was motivated by family, the swiftness of his exit left his character arc feeling somewhat incomplete, despite his consistent presence and contributions to the Firehouse 51 dynamic. His absence created a notable shift in the ensemble’s younger generation.

Moving into the more emotionally impactful departures, Sylvie Brett’s exit from Chicago Fire marked a pivotal moment. Portrayed by Kara Killmer, Brett was a paramedic on Ambulance 61, introduced in Season 3 as a replacement for the beloved Leslie Shay after her tragic death. Brett faced the daunting task of filling significant shoes, but over the years, she not only rose to the occasion but became one of Firehouse 51’s most integral and admired members. Her journey was characterized by immense growth, from a somewhat naive newcomer to a confident, compassionate, and capable paramedic, eventually taking on a leadership role. Brett’s backstory, discovering she was given up for adoption by a teenage mother named Julie, provided rich narrative material, culminating in her witnessing Julie’s death in Season 8. Beyond her professional life, her relationship with Captain Matthew Casey became one of Chicago Fire’s most enduring and cherished romances, affectionately termed “Brettsey.” Their slow-burn love story, evolving over multiple seasons and challenges, deeply resonated with viewers. Her final episode, Season 12, Episode 6, “Port in the Storm,” offered a beautifully crafted send-off: she married Casey in a heartfelt ceremony and subsequently moved to Portland, Oregon, with her adopted daughter, Julia, to join Casey and his two adopted sons, Griffin and Ben Darden (whom Casey had moved to Portland to care for in Season 10). Brett’s departure, framed by love, family, and a new beginning, provided a rare sense of complete closure, a fitting end for a character who had become the emotional core of Ambulance 61. It represented the natural, happy progression of a character finding personal fulfillment beyond their demanding career.

Detective Hailey Upton’s departure from Chicago P.D. was another profoundly affecting exit in 2024, placing high on the list of heartbreaking goodbyes for fans of the franchise. Portrayed by Tracy Spiridakos, Detective Upton joined the Chicago Police Department’s Intelligence Unit in Season 4, stepping in after Detective Erin Lindsay’s exit. Initially a recurring character, Upton’s sharp intellect, intense dedication, and complex persona quickly elevated her to series regular status in Season 5. She developed into one of Sergeant Hank Voight’s most trusted detectives, often mirroring his morally ambiguous methods while grappling with her own ethical boundaries. Upton’s character arc was defined by her resilience in the face of deep personal trauma, stemming from a childhood where her father subjected her mother, siblings, and her to abuse. Her professional life was deeply intertwined with her personal relationships, most notably her marriage to and eventual separation from Detective Jay Halstead. Following Halstead’s exit in Season 10, Upton’s character shone even brighter, cementing her role as the primary female lead detective and demonstrating immense strength and independence. Her final season, Season 11, saw her take the lead on several crucial investigations, including the intense search for a kidnapped Voight in the season finale. Detective Upton’s blend of vulnerability, fierce determination, and complex internal struggles solidified her as one of Chicago P.D.’s most compelling figures. Her departure leaves a significant void in the Intelligence Unit, fundamentally altering its dynamic and the way it operates, particularly in its ongoing battle against Chicago’s most dangerous criminals.

However, the most profoundly heartbreaking exit from the One Chicago universe in 2024 undoubtedly belonged to Chief Wallace Boden, a pillar of Chicago Fire since its inception. Portrayed by Eamonn Walker, Boden was not just the Deputy District Chief for the Chicago Fire Department but the unwavering heart and soul of Firehouse 51. He stood as one of the last remaining original series regulars on Chicago Fire and was the sole original character across the entire One Chicago franchise to make a full-time exit in the past year. While characters like Severide and Casey often took center stage in high-octane episodes, Boden’s omnipresent leadership, moral compass, and profound impact were felt by every firefighter and paramedic who passed through Firehouse 51’s doors, as well as by the viewers who had watched him for over a decade. His leadership was a unique blend of stern authority and deep paternal compassion, holding his diverse squad together through countless crises, personal struggles, and professional triumphs. The significance of his role was powerfully underscored in his final episode, “Never Say Goodbyes,” which featured an emotional gathering in his office where the entire Firehouse 51 team — including Herrmann, Cruz, Kidd, Violet, and many others — came together to offer heartfelt farewells. This scene served as a poignant testament to the immense respect and love they held for their chief. Boden’s full-time departure represents an unprecedented shift for Chicago Fire, as it is difficult to envision the series without his constant, grounding presence. The silver lining for fans is the news that Chief Boden will remain in a recurring capacity for Season 13 and potentially future seasons, meaning his influence will not be entirely erased. Nevertheless, his stepping back from full-time duty marks the end of an era, signifying the biggest change to the core fabric of Firehouse 51 in the show’s history and leaving an irreplaceable void in the franchise.

The exits of these diverse characters in 2024 have significantly reshaped the narrative landscape of the One Chicago franchise. From the controversial professional demise of Dr. Ahmad to the bittersweet, hopeful send-off for Sylvie Brett, and the profound, almost unimaginable departure of Chief Boden, each exit has contributed to the ongoing evolution of these beloved shows. These transitions serve as powerful reminders of the transient nature of even the most established roles in long-running television series, while also opening new avenues for character development and fresh storytelling as the One Chicago universe continues to move forward.