We know who's leaving Chicago Fire in the upcoming season. Darren Ritter (Daniel Kyri) and Sam Carver (Jake Lockett) have been shown the door, even though there are a few episodes left in the current season. We're not here to talk about them, though. We're here to discuss the characters who are essential to the show's make up.
Ritter and Carver are going to be major losses, but the show will survive without them. The four characters we've selected below are exceptions to this rule. It would be hard to imagine Chicago Fire without them, and as such, we're confident they will stick around for season 14. At least we hope. My goodness, can you imagine?
Christopher Herrmann

Christopher Herrmann (David Eigenberg) may be doing increasingly less as a firefighter, given his hearing-related injury in season 12, but he remains vital as ever to Firehouse 51. He was the one that Wallace Boden (Eamonn Walker) earmarked to become the new chief, and his reluctance to do so has led to some intriguing moments of self-reflection.
Herrmann is representative of the old guard at 51. Moreso than even Mouch (Christian Stolte), who would also be a colossal loss, Herrmann's grizzled approach and overall presence makes him one of Chicago Fire's indispensable characters.
Stella Kidd

The notion of writing Stella Kidd (Miranda Rae Mayo) off Chicago Fire boggles the mind. Her absence would not only compromise the way that Firehouse 51 operates, but it would destroy the arc that her husband, Kelly Severide (Taylor Kinney) has build alongside her for several seasons.
Kidd may not always be around (she's one of the many characters who have missed an episode in season 13 due to NBC's desire to cut costs), but she's always present when something important matters, and she's about to become a mother. We'd say she's about as safe as a character gets.
Joe Cruz

This one is a little different because Joe Cruz (Joe Minoso) isn't as vital to the plot of Chicago Fire as Herrmann or Kidd. He's pretty peripheral when it comes to weekly stories, and has settled nicely into the role of unassuming dad who sometimes gets spotlit in a standalone episode.
Make no mistake, though, people were be unhappy if Cruz was forced to leave the show. He's one of the most beloved characters in Chicago Fire history, and some fans are still reeling from the exit of his best friend, Otis (Yuri Sardarov), years ago. Getting rid of Cruz feels like a bridge too far, and we don't think the writers/producers would consider it.
Kelly Severide

Obvious? Perhaps. Accurate? You bet. It was difficult to lose Matt Casey (Jesse Spencer) seasons prior, given how important his bond with Severide was to the show's success, but the brief window of time when it felt like we were going to lose Severide too (season 11) was worse. He's the Sam Malone of Chicago Fire, the leader who's very presence unifies the rest of the characters and the stories.
Severide can do a lot with a little screen time, and his transition to fatherhood promises to be one of the most exciting developments in the show's history. Keep Severide at all costs would be our advice, and thankfully, this seems highly likely.