Casey (Jesse Spencer) may encounter some serious trouble in episode 19 of "Chicago Fire" season 5.

Titled "Carry Their Legacy," the official synopsis for the upcoming episode reveals that the Firehouse 51's rig will break down in the field. With this, Casey and his old friend and colleague Jason (guest star Kamal Angelo Bolden) will be reunited, as the latter helps Casey and the rest with a temporary accommodation until the issue with the rig is fixed.

In the promotional preview of episode 19, the firefighters are looking into a manhole that seems to be emitting some smoke. It seems that a fellow firefighter is stuck inside and is in need of help. In order to find out more about the incident, Casey volunteers to go in. As Casey helps his fellow firefighter inside the manhole, his teammate suddenly bellows his name. After which, a huge explosion takes place.

The situation looks serious, as the preview teases that "it's the call that they never want to get and the moment that will change everything." Will Casey survive the explosion?

Aside from this, Dawson (Monica Raymund) and Brett (Kara Killmer) will continue to train the new recruits in the upcoming episode. Earlier in the show, Boden (Eamonn Walker) asked both of them to look after the newbies, but Dawson and Brett were quite reluctant about it. Nonetheless, Dawson and Brett will eventually find satisfaction in sharing their knowledge to the new recruits.

As for Severide (Taylor Kinney), he will continue to fix his relationship with Anna (Charlotte Sullivan). The summary teases that Anna will be looking for support from unlikely sources, but it is still uncertain who at this point. On the other hand, Connie (DuShon Brown) comes back from her family engagement.

"Chicago Fire" season 5 airs episode 19 on Tuesday, April 25, at 10 p.m. EDT on NBC.