Kara Killmer on final ‘Chicago Fire’ episode, Jesse Spencer

She’s flaming out.

Kara Killmer appeared in her final “Chicago Fire” episode on Wednesday, Feb. 28. 

Now in Season 12, the NBC show follows the lives of the firefighters and paramedics working at the Chicago Fire Department at the firehouse of Engine Company 51, Truck Company 81, Rescue Squad Company 3, Ambulance 61 and Battalion 25. 

Killmer, who joined in Season 3, announced in November that she would be leaving the series after a decade in the role of paramedic Sylvie Brett. Before leaving, though, Sylvie will tie the knot with Captain Matthew Casey (Jesse Spencer). 

“I think this is a natural conclusion for my character,” Killmer told The Post.

“I sort of am selfishly delighted over the fact that she started as a jilted bride,” she said.

“She was dumped at the altar by her high school boyfriend, and then runs off to Chicago to start her life over, and ends up across the aisle from the love of her life, the most eligible bachelor in all of Chicago and Portland. I’m so grateful that the writers gave her this happy ending that everyone who’s been on the journey with her for ten years has wanted for her. To finally let her resilience pay off and finally get everything that she’s always hoped for.” 

About working with Jesse Spencer, 45, who left the show in 2021 but has returned for guest appearances, she said, “I learned so much from him. He is such a fantastic actor and such an incredible leader, on screen and off screen as well. He always has a good attitude. He’s so intentional about his work. He has a good relationship with everybody.”

“He’s one of those people everyone he interacts with, you can be standing on one side of the room and go, ‘Oh, yes, I was just drawn to Jesse Spencer.’ And somebody on the other side of the room will be like, ‘Jesse Spencer. I love that guy.’”

According to Killmer, “everybody trusts him” on set. The Australian native has been an audience favorite since leading the series when it debuted in 2012.

“He just did such a great job of keeping control and nuance in his performances,” Killmer told the Post. “You want to fight for the things that he fights for. And, you’re always rooting for him. That was true in life as well. He’s such a fantastic scene partner. If you had told me whenever I first started working on this show that our characters would end up together, I would be like — pinch me. He is a lot of fun.”

Brett has been a “hopeless romantic” from the start. But despite her flings with Cruz [Joe Minoso], Antonio [Jon Seda] and the chaplain [Teddy Sears], among others, her relationship with Casey always stood out to her.

“I think what’s unique about Matt is that he never asked her to compromise. He always brought out the best in her,” she said. “I love that they end up together, because I think they do bring out the best in each other.”

Her last day on the show was their wedding reception, which made it feel like “one big party.” 

“I got to finish my time here in a gorgeous dress, eating a lot of cake, doing something akin to the jitterbug with Jesse Spencer and the whole cast. It was perfect closure for Sylvie and for me,” she explained. “One of the things that I’m the most grateful for is that ten years is a long time. It is such a privilege to have spent ten years in the storage space of first responders. Because we work hand in hand with real firefighters, real police officers, real paramedics, every episode, every single day. There is something very special about people who choose to be servicemen and women.”

“Our goal always as actors is can we capture a fraction of the self-sacrifice, the brotherhood, the humor, the grit that these people, embody?” 

About whether she may return to the show in the future, she said, “The door is wide open. I’m happy to come back anytime. 51 is notorious for getting itself into all kinds of trouble…if they need Sylvie back any time, any day. Happy to do it. We love to see familiar faces on this show. We love homecomings.” 

“Chicago Fire” airs Wednesdays at 9 p.m. on NBC.