Chicago's first responders unite in the wake of a catastrophic gas explosion and fire that threaten a city government building. Herrmann reluctantly shadows Pascal while Violet, Novak and Dr. Frost take charge of triage efforts on site. The crossover continues on Chicago Med S10E11 In the Trenches (II) and Chicago P.D. S12E11 In the Trenches (III).

Cast: Taylor Kinney, David Eigenberg, Joe Miñoso, Christian Stolte, Miranda Rae Mayo, Daniel Kyri, Hanako Greensmith, Jocelyn Hudon, Jake Lockett, Dermot Mulroney