Watch a Preview of Tonight's Dramatic Series Finale of 'Rescue Me'

When "Rescue Me" premiered on FX back in 2004, the idea of Dennis Leary in a firefighting drama seemed a little...off. Known for his acerbic comic wit and for being in a series of comedies that even he acknowledged as being pretty bad, Leary simply didn't have much background in doing serious television.

Nonetheless, the well-written and acted drama ended up being a perfect fit for Leary, and the role of cynical, self-destructive alcoholic firefighter Tommy Gavin ultimately ended up being the best work the actor has done outside of his early standup.

The show comes to an end tonight a few days before the 10th anniversary of 9/11, and Leary told audiences recently what they should expect about the dramatic finale.

Warning: Spoilers Ahead

Leary isn't saying who, but apparently somebody important dies.

"Staying true to the nature of the show, it was important that somebody or somebodies were going to have to pay the price," Leary told the Television Critics Association, according to Starpulse.

"Because we were dealing with grief, it was a great thing for all the characters on the show to have to deal with again. It’s also the nature of what these guys do for a living. It’s such a life and death job that that never went away from the show. We didn’t think it was the right way to go out without dealing with that again," said Leary.

As both Leary and the FX promos have let on, there's a big fire in the finale, and the guys at 62 Truck deal with a very difficult aftermath.

According to Leary, the last scene involves "about 150 firefighters, down on the waterfront in New York. It was a very complicated shot. That was the last thing that we shot, actually. It was nice."

Watch the preview for the "Rescue Me" season finale below: