In this exclusive clip, as they're en route to a gruesome scene involving a young girl who was impaled after falling through a skylight, Dawson and Sylvie (Kara Killmer) find themselves caught in a horrible traffic jam.
"Sirens don't mean a thing to anyone anymore," Dawson, who's behind the wheel, gripes to Sylvie, taking her eyes off the road for a split-second. And that's all it takes for an oblivious pedestrian to step out into the path of the oncoming ambulance. Unfortunately, Dawson's reflexes and quick-thinking aren't enough to prevent an accident from happening in this situation. It's a safe bet they won't be responding to Herrmann's (David Eigenberg) call anytime soon.
Check out the sneak peek -- but be prepared to wince.
Chicago Fire airs Tuesdays at 10/9c on NBC.