The firefighters and paramedics of Firehouse 51 risk their lives to save and protect their city. As these heroes forge headfirst into danger, the choices they make can mean the difference between life and death. But from the relentless pressure of saving lives, an extended family is forged. Led by Chief Wallace Boden, Matthew Casey, Kelly Severide, Sylvie Brett and the others know¿when it's go time, Firehouse 51 lays it all on the line for each other.