Grief and laughter, back to back, is what Denis Leary says he saw inside FDNY firehouses after 9/11, and it became the core of “Rescue Me.”

“A lot of the guys I knew that had survived, I was spending time with them and in their firehouses as they were digging through The Pile in the fall right after 9/11,” Leary told the New York Post. “We were witnessing the grief that they were going through.”

Leary said he and writer Peter Tolan had originally been working on a story about a firefighter killed in the line of duty, but one moment shifted the direction of the show.

“It was literally in the blink of an eye,” he said. “We went from watching a guy come up from downtown from ‘the pile’ – they had found a friend, a piece of a friend, and so he was just overwhelmed with grief. I mean, he could barely talk.”

“Watching him trying to fight to talk in that firehouse kitchen was a very tough experience to watch,” Leary recalled. “Maybe 20 minutes later… all of us were laughing about something.”

Leary said that swing from grief to laughter helped shape the series.

“We’re going to make a show where people are on the edge of their seat watching an action sequence involving fire,” Leary told the outlet. “And then the next minute they’re crying because they’re so sad, and then the minute after that, they’re laughing their a–es off.”

“Rescue Me” starred Leary as Tommy Gavin, a veteran New York City firefighter dealing with alcoholism, family turmoil and survivor’s guilt after the Sept. 11 terrorist attacks. The cast also included Andrea Roth, Michael Lombardi, Steven Pasquale, Daniel Sunjata, John Scurti and Jack McGee.

Leary said the show’s creators had no shortage of material from firefighters and consultants.

“We had so much information on a daily basis, not just comedically, I’m talking about dramatically,” he said. “All the ideas for our fires came basically from experiences those guys had.”

He said younger firefighters responded strongly before the show premiered.

“They said, ‘You got it. You totally nailed it.'”

Leary also recalled where he was on 9/11. He said he had been playing pick-up ice hockey and watched an “endless flow” of dust-covered corporate workers heading uptown New York City for hours from the West Side Highway.

“They turned the rink into a morgue, and they lined up all the ambulances,” he said.

Leary added, “The sound of the buildings … it’s almost like it goes into your bones.”

He had already experienced the bond among firefighters years earlier, after his cousin and close friend Jeremiah Lucey died with five other Worcester firefighters in a 1999 warehouse fire. He recalled FDNY friends traveling to Massachusetts to help search the ruins.

Leary launched the Leary Firefighters Foundation in 2000, shortly before the 9/11 attacks killed many FDNY firefighters and friends of Leary.

“I knew I was going to hear about firefighter friends of mine from the FDNY that didn’t make it,” Leary recalled. “But the next day, to hear that ‘Ace’ Bailey had died in the thing as well, we were just like, ‘That is crazy.’ I mean, it’s insanity.”

“Rescue Me” premiered on FX on July 21, 2004, and ran for seven seasons, ending in September 2011.

Leary said some people in Hollywood doubted audiences would want comedy after 9/11.

“I remember a network executive saying to me at the time or a movie executive saying this is going to alter the way people feel about comedies,” Leary said during an appearance on Joy Behar’s show in 2011. “And I was like, ‘What are you talking about? They’re going to need to laugh more than ever. If anything, they are going to be looking to laugh.’ And he was full of fear.”

Speaking alongside Leary at the 9/11 Memorial & Museum in 2024, Tolan said making a series around such a personal tragedy carried weight.

“When you know that, you always have to sort of be vigilant to how far am I going and is it too soon to do this? And I’m not going to say that we were hugely careful because there are elements of the show that are raucous – that are just inappropriately funny,” Tolan said. “But that’s the human experience.”

“That is what happens, that is the most pure essence of how people move forward in their lives – is at a certain point, they’re able to laugh,” he added. “Not about the event, but about how they’re dealing with the event and how they are responding to it.”

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