After 12 seasons, Chicago Fire fans have had to say goodbye to many of their favorites, from Captain Matthew Casey to most recently Paramedic-in-Charge Sylvie Brett.
Here we take a look at those main cast members who left and why…
Kara Kilmer:
Kara played paramedic Sylvie Brett for 10 years but left during season 12 after getting married to Station 51's former Captain, Matt Casey, and moving to Portland, Oregon with him. The decision was a creative one, rather than one made by Kara, but showrunner Andrea Newman told TellTale TV that Kara "understood the Matt/Sylvie connection, she felt it as deeply as anyone" and so knew it was the right decision to write her out.
Matt (played by Jesse Spencer) returned for the episode that saw them get married in a fish store (after a comedy of errors that involved miscommunication with Squad 3 member Tony) before enjoying their reception at Molly's pub.
Their ceremony featured emotional vows that included a terrible fire pun by Matt, and Kelly Severide (Taylor Kinney) returning to Chicago for his best man duties.
They were last seen driving off with Matt's foster sons, the children of his late best friend Andy Darden, and Syvlie's adopted daughter Julia.
Jesse Spencer as Lieutenant Matthew Casey
Jesse Spencer left fans devastated when he left the show in 2021. The actor decided to bow out of the drama after ten years, with his character Matthew Casey bidding farewell to the Windy City and attempting a long-distance relationship with then-girlfriend Sylvie Brett.
On leaving the show, Jesse said: "I realized I'd been doing TV for a long time, so I added it up… We were coming up on the 200th episode and I called Derek to break the news that it was time for me to leave the show. He agreed we should at least get Casey to the 200th episode. It was a difficult decision because I've loved the show from the start but there are other things I'd like to do in the future. There's family I need to take care of, and 18 years is a long time."
Jesse has enjoyed a busy schedule since leaving the NBC show. Earlier this year, he made a one-off return to Australian soap opera Neighbours, where he first started his career, for the show's final ever episode. He is also set to appear in Disney +'s upcoming Australian dramedy, Last Days of the Space Age.
He returned to Chicago Fire for several key episodes, and then married Sylvie in season 12, episode six, which led to Sylvie's departure from the show.
Alberto Rosende
Shadowhunters star Alberto joined Chicago Fire in season eight as Firefighter Candidate Blake Gallo. A daredevil who felt invincible losing his entire family in a house fire as a child, he learned how to control his impulsive instincts and became a valuable member of Firehouse 51.
In November 2023, it was revealed that he would be leaving the series after the season 12 premiere; in season 11 he discovered he had long-lost family and the opening episode of season 12 revealed he would be moving to Michigan to get to know them.
“When I decided to end my time with Chicago, it wasn’t easy. The people I’ve met were truly special, the friendships I’ve made will last a lifetime, and the story I got to tell was one that made me proud. Can’t wait to see what else is in store and I wish everyone the best in shooting the rest of the season.” Alberto shared via Instagram Story.
Monica Raymund as Paramedic Gabriela Dawson
Monica Raymund left the show in 2018 after six seasons of playing Gabriela Dawson. The actress couldn't stay away for long, however, as she briefly returned for the season seven premiere as well as for one episode in series eight.
On making the decision to walk away from the show, the actress told the Chicago Tribune that she felt "hungry to explore a different role". "I had been in Chicago for five years and just personally where I was in my life, I was ready to create my home and kind of plant some roots in Los Angeles," she added.
The actress is currently starring in Starz crime drama Hightown as Jackie Quiñones.
Lauren German as Paramedic Leslie Shay
Lauren German played Leslie Shay in the NBC drama for the first two seasons until her character was killed off in the dramatic series finale. Leslie was out on a call when she was fatally struck by a collapsing pipe. It was later revealed that the fire was caused by a serial arsonist who was stalking her.
Executive producer Matt Olmstead spoke about the reason behind her exit to TV Line, saying: "Going into it, we knew if we were going to do it, it had to be someone who was going to give us a big impact, as opposed to going for a lesser-known character."
He added that Lauren was "very professional" about leaving the show and even confessed that she wouldn't "miss the Chicago winters".
Not long after her departure from the show, Lauren landed a role in fantasy crime drama Lucifer opposite Tom Ellis, which ran from 2016 until late 2021.
Charlie Barnett as Firefighter Candidate Peter Mills
Charlie Barnett's exit from the show came not only as a surprise to fans but to the actor too! Charlie, who left the drama in 2015, told the Sarasota Herald-Tribune that he was told about his departure on what he thought was "a normal day of filming".
"They expressed that it wasn’t about me or myself as an actor or my personality," he said. "But they felt that Peter had reached a plateau and the writers didn’t know where to take him because he’s done so much already."
Being let go from the show may have been a blessing in disguise for Charlie, however, as he went on to land several major TV roles in the subsequent years. After appearing as a minor role in Netflix's Orange Is the New Black, he went on to star in two of the streaming site's most popular shows, including comedy-drama, Russian Doll, and season two of You.
Teri Reeves as Doctor Hallie Thomas
Teri Reeves played physician Hallie Thomas, Matthew Casey's girlfriend, for 11 episodes in the first series before she was tragically killed off. It was revealed that Halli had been murdered by convicted arsonist Tim Campbell, who was eventually shot.
While the exact reason why Teri left the programme is unknown, it has been reported that the producers chose to kill her off in order to build the dramatic stakes in season one.
Since starring in the NBC show, the actress has gone on to appear in several major TV series, including Grey's Anatomy and Lucifer, both of which she featured in for one episode. Viewers may also recognize her for playing the roles of Dorothy Gale in Once Upon a Time and Marlena Olin in The Punisher.
Yuriy Sardarov as Firefighter Otis Zvonecek
Yuriy Sardarov played fan-favorite character Otis Zvonecek for seven seasons before he was dramatically killed off in the season eight premiere.
The firefighter was called out to battle at a mattress factory and became trapped in the fire after being hit by an infernal backdraft.
Chatting about the star's exit, creator Derek Haas revealed that instead of placing a major character in danger only to save them, he wanted the audience "to be reminded that these calls are dangerous and sometimes people don’t make it".
"We thought, what if we killed off Otis and he dies heroically? We realized there was so much emotional landscape we could cover," he told TV Line, adding that it "needed to be a core cast member".
After leaving the NBC drama, Yuriy went on to appear in two episodes of ABC's The Rookie, playing the role of Trevor Gurin.
Like this story? Sign up to our What to Watch newsletter to get other stories like this delivered straight to your inbox.