Randy Flagler

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

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.

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.

An out of control apartment building fire finds Casey laying it all on the line.

Gibbs' long-suppressed memories overwhelm him as he recovers from injuries he sustained in a terrorist bombing.

Lincoln and the team go to Las Vegas where Sucre gets an indecent proposal; Sarah finds out about Michael's condition; Roland pushes his luck; T-Bag and Gretchen team up; the secrets in Whistler's bird book are revealed.