“Thank you for the privilege of playing sweet Sylvie for 10 [years],” Killmer, 35, wrote via

X on Wednesday, February 28, after her character, Sylvie Brett, said goodbye on the show.

“I will forever be humbled by all of the 1st responders I’ve been honored to work with.”

The actress gave a shout-out to her One Chicago family, adding, “All of my love to the best cast and crew in the business. Chicago will always have a piece of my heart! @NBCOneChicago @WolfEnt.” Us Weekly confirmed in November 2023 that season 12 would be the last for Killmer, who joined the series as a paramedic during season 3. Killmer didn’t address her exit at the time but teased earlier this month that her exit might not be permanent. “The door’s open for me,” Killmer told Entertainment Weekly ahead of Wednesday’s farewell episode. “I’m happy to come in anytime they want to bring me back. [Firehouse] 51 has a unique way of getting itself into trouble, and if they need Sylvie to come through and tell ’em what’s what, I will be there.”

During the episode, Brett finally got to marry the love of her life, Matt Casey (Jesse Spencer). While the wedding didn’t go off without a hitch — Brett was held at gunpoint before tying the knot at a fish store — fans did see the couple become husband and wife. Following the Brettsey nuptials, the Chicago Fire cast shared several tributes to Killmer regarding her last episode. “It’s been an absolute pleasure working with you @karakillmer,” Spencer, who exited the firefighter drama after 10 seasons in 2021, wrote via X on Wednesday. He shared a photo of his return for the wedding episode alongside a pic of Killmer during her first few seasons.

Spencer, 45, added: “You are a scholar and a pro. Thank you for the good times and bad. Your presence at this ol’ firehouse will be missed. Happy wedding day!!” The rest of the cast filmed a goodbye video for Killmer, which the show shared via its official Instagram account. In the clip, David Eigenberg, who plays Christopher Hermann, said, “We’re going to miss you, like, you’re going to break our [heart],” before making a hand heart on set with Daniel Kyri, who plays Darren Ritter. “We love you Kara,” Kyri, 29, chimed in. The camera then switched to show Killmer’s ambulance partner Hanako Greensmith, who portrays Violet Mikami, and added, “I love you, Kara.” Christian Stolte, who has been playing Randall “Mouch” McHolland since the 2012 premiere, gushed about Killmer as well. “What I really don’t want to do right now is say goodbye to my sweet, brilliant, talented friend Kara Killmer,” he confessed. “It has been a gift to work with you all these years. … I will miss you.”