"Chicago Fire" might be going for a double whammy in its season 4 finale so fans should probably get ready with the tissues.

Things were already tense in the previous episode between Severide (Taylor Kinney) and Kidd (Miranda Rae Mayo) as her volatile ex returned to the scene, while Dawson (Monica Raymund) and Casey (Jesse Spencer) butt heads over the former's decision to foster Louie. Jimmy (Steven R. McQueen) and his older brother, Danny, also had a little falling out when he decided against helping his brother's plan to ask a favor from Casey. But before the two brothers could patch things up, both were called to a collapsed building. Fans were then shocked and heartbroken when the show's penultimate episode saw Jimmy unable to save his older brother Danny when the building collapsed on it.

The finale of "Chicago Fire's" fourth season will see the first responders in mourning, but it seems that history might sadly repeat itself. In episode 23, Jimmy lashes out at Lt. Boden (Eamonn Walker) in the aftermath of Danny's death. Kidd deals with her ex, Grant (Guy Burnet), while Dawson takes another step forward in her pursuit of fostering Louie. Meanwhile, Casey's Alderman duties take him out of town with his political consultant, Susan Weller (Lauren Stamile). But 51's latest call once again endangers one of their own.

A trailer for the upcoming finale, "Superhero," teases that Dawson might not live long enough to be a mother to Louie. The clip starts with Jimmy at the lockers, looking at a picture of him and Danny when they were young. He's later seen in Boden's office. The chief tells him his brother died a hero, but Jimmy counters that Boden was the one who got Danny killed. As expected, this didn't go down well with Boden.

Dawson and Casey are also shown engaged in a tense confrontation. She tells Casey she wants to foster Louie and accuses him of not being ready for it. The scene quickly shifts to 51's next case, a building with flames spewing out from one floor. Boden shouts orders for the remaining firefighters to get out. Dawson orders Kidd out then pulls seniority over her when she refuseS. Kidd is shown rappelling down, as Severide and Boden look on tensely. The clip ends with the floor exploding and Boden's voice calling for Dawson. But all he's getting is radio silence.

Another death on top of Jimmy's loss might be too much for Firehouse 51 and the show's avid viewers. But there's nothing they can do but brace themselves for the emotional finale that showrunner Matt Olmstead and his team concocted. The EP told The Hollywood Reporter that they opted for "a real touching, heartwarming ending coupled with a major threat, cliffhanger."

The finale of "Chicago Fire" season 4 will be aired on May 17 at 10 p.m.