Warning! Spoilers ahead for Chicago Fire season 13, episode 19.After Chicago Fire season 13, episode 19, it becomes clear that NBC is getting rid of the wrong Firehouse 51. As one of the longest-running shows on broadcast TV, One Chicago is no stranger to cast reshuffles. Over the years, it has gone through multiple cast changes for various reasons — some of them were initiated by the actors, other times, they were for story or cost-cutting purposes. Despite its fairly regular occurrence, it is always tricky to say goodbye to any character, especially those who have been in the show for a relatively long time.