Mo Gallini

For the firefighters, rescue squad and paramedics of Chicago Firehouse 51, no occupation is more stressful or dangerous, yet so rewarding and exhilarating.

Severide hides his serious shoulder injury as he tries to rescue a construction worker from a collapsed building; two teens are trapped in a vehicle.

Casey must decide whether to turn in a cop's son who paralyzed a teen in a drunken-driving accident; Severide learns he has a fractured vertebra; Mills is torn between his mother and the job.

Chief Boden faces allegations after the death of a homeless man in a warehouse fire.

Casey must face the consequences of confronting Detective Voight; Dawson faces disciplinary action; Severide reaches out to an old friend about his injury.