What Makes 'Chicago Fire' Must-See TV?

The cast of NBC's upcoming drama Chicago Fire sat down with ET to dish on why they couldn't turn down their roles and why this show will be a must watch this fall.

"When I read that script, it was very filmic," said Eamonn Walker (E.R.), revealing what initially pulled him in to the project. "What [show creators] Derek [Haas] and Michael [Brandt] wrote was a movie with people and characters that you fell in love with almost instantaneously."

The show chronicles the lives of the firefighters, Rescue Squad and Paramedics of Chicago Firehouse 51. The series is said to find a happy medium between the action of the job and the drama of the characters' personal lives, which in turn affects their work relationships.

Although David Eigenburg (Sex and the City) was immediately drawn to the script, he may have been discouraged by the character he was chosen to audition for.

RELATED: 10 Promising New Fall Shows

"The first character description for my character, Herman, was that he was tall," said the actor, who's listed at 5'7 ½" on IMDb.com. "I literally for the first time in my life put some lifts in my shoe, so I was about two inches taller."

Any doubts Eigenburg harbored quickly dissipated when he was welcomed into the audition room.

While the job may have been a dream opportunity for the cast, it does come with a fair amount of work.

"It really is physically demanding," said Jesse Spencer (House M.D.), who revealed that their wardrobe consists of actual firefighter gear weighing up to 70 lbs.

Watch the video for more. Chicago Fire premieres on NBC Wednesday, October 10 at 10/9c.