Mayo and the rest of the Chicago Fire cast bid Killmer farewell after her last-ever episode of the series.

Is someone chopping onions in here? Get ready to cry over Sylvie Brett leaving Station 51 all over again when you read Miranda Rae Mayo’s (Stella Kidd) goodbye post for Kara Killmer (paramedic Sylvia Brett) on Instagram.

These real-life besties have the sweetest friendship, and thank goodness that doesn’t have to end even as the cast of Chicago Fire changes over the years.

Mayo kept her message for Killmer short and sweet, writing: “The blessing and miracle that is @karebearacares I know this won’t be the last time we see you at 51  See you soon sister,” perhaps hinting at a cameo to come?

She also included plenty of adorable behind-the-scenes moments, starting with an instant picture from the Brettsey wedding.

In other photos, Killmer relaxes with her co-stars and poses on the beach. In the fifth slide, she’s very excited about a cookie, and in the sixth, she literally jumps into Mayo’s arms. There are more snaps of the ladies embracing, showing just how deep their bond goes after so many years working together.

“ ,” Hanako Greensmith, who plays paramedic Violet Mikami on the series, commented.

The Chicago Fire cast says goodbye to Kara Killmer
Of course, Mayo wasn’t Killmer’s only friend on set.

The Chicago Fire cast wished her a bon voyage in an adorable video montage that included heart hands and heartfelt remembrances. Christian Stolte (Mouch) recalled, “Kara. it has been a gift to work with you all these years, the dedication you brought to the show, the times you’ve advocated for me personally, I’ll never forget it. You are an infinite, bottomless reservoir of mirth, and simply a joy to be around. I will miss you, I will miss your beautiful family, and it goes without saying that things will not be the same without you.”

Killmer’s final episode was Season 12, Episode 6, “A Port In The Storm.” Her character got a happily-ever-after ending, with Sylvie marrying her longtime love Casey (Jesse Spencer) and moving to Portland to be with him and her adopted daughter Julia.

In an interview with TVLine, showrunner Andrea Newman explained why long-running characters like Brett need to have organic departures. “[In] storytelling and in terms of real life, 12 years is a long time and things need to change, just dynamic-wise. You want new characters and you want new dynamics. Actor-wise, 12 years is a long [time]. Nobody expects in TV [that] they’re going to be anywhere for 12 years.”