9-1-1: The 118's Troubles Are Just Getting Started in This Exclusive Season Finale Clip

The first responders of 9-1-1 are usually called to the scene of an emergency to save Los Angeles civilians. But in Monday's season finale of the Fox (and soon-to-be ABC) procedural drama, the 118 will be forced to save each other when the ground literally falls out from beneath their feet.

In TV Guide's exclusive sneak peek of the episode, the fan-favorite firefighters — Bobby (Peter Krause), Chimney (Kenneth Choi), Hen (Aisha Hinds), Buck (Oliver Stark), Eddie (Ryan Guzman), and Ravi (Anirudh Pisharody) — arrive on the scene of a massive car pile-up on a freeway. Among the victims are Jo and her late mother's best friend Mallory, who were on a road trip when their camper van was rear-ended.

But as the synopsis for the episode warns, the initial car accidents are just the tip of the iceberg; they will lead to a catastrophic overpass collapse that will endanger the lives of civilians and firefighters alike. Apart from the terrifying emergency, the finale, which will wrap up a six-season run on Fox before moving to ABC next season, will see the rest of the ensemble react to the news of Maddie (Jennifer Love Hewitt) and Chimney's engagement, as well as the resolution of some other important personal relationships that would carry over to the seventh season (and get some fans talking in the interim).

"With the 118, let's just say there will be some perilous situations, most likely for more than one member of this first-responder group," Choi told TV Guide in an interview last month. "And it will be explosive, it'll be cataclysmic, and the finale of this season, especially, is gonna be worth watching."

9-1-1 airs Mondays at 8/7c on Fox. Episodes are available to stream the next day on Fox Now or Hulu.