On Wednesday 20 October the hit NBC show will air it's 200th episode, and the stars - including Jesse and Taylor who have been with the series since episode one - took to social media to share their love.
WATCH: Chicago Fire stars Taylor Kinney and Jesse Spencer celebrate special milestone moment
"Thank you so much for helping us get to 200 episodes, we can't believe it ourselves," said Jesse opening the video, while Taylor closed it by sharing: "All of you that have been with us watching over the years, we wouldn't be here without you so lots of love, thank you, God bless."
"Thank you to all the fans out there," added Daniel Kyri while co-star Christian Stolte joked: "We couldn't have done it without you, well, we could have but no one would have seen it so and what would have been the point?"
"Just want to say thank you to all you wonderful people for watching 200 episodes, you're the best," added David Eigenberg.
The fifth episode of season 10, called Two-Hundred, has already teased Jesse's character Matthew Casey's departure with a promo that revealed emotional words from former Battalion Chief Boden, as well as flashbacks of Casey's years at Firehouse 51.
Taylor and Jesse celebrated with a special cake on set in Chicago
It is unclear what decision Casey will make but one of the biggest indications that Jesse could be leaving is showrunner Derek Haas' recent comments.
In an exclusive interview with HELLO!, he teased that viewers can expect heartache for the Captain and paramedic-in-charge, Sylvie Brett - who finally found romance after years of will-they-won't-they - admitting that things aren't going to be "all roses" for the fan favorite couple.
In the most recent episode of the firefighter drama, Casey took a trip to Oregon to check in on Griffin and Ben Darden, the sons of his late friend, Andy.
Tony, David, Taylor, Jesse, Eamonn, Christian, Joe and Randy have all been with the show since episode one
However, what he found was not good; the teenage boys were living on their own and had fallen into some bad habits, including recreational drugs.
Although Casey hoped to move them to Chicago to be with him, he was told they needed to stay in Oregon, leaving him with a big decision: send them to a foster home or upend his life.
"He certainly had other things come up over the years that might have cost him his job or suspended his job for a while, and he’s overcome them all, but we’re in a little bit of a no-way-out situation here," Haas told TVLine of the decision Casey now has to make.
One Chicago airs Wednesday at 8/7c on NBC
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