NEW YORK -- Given the circumstances, Mike Piazza’s go-ahead home run in the first game in New York City after the Sept. 11, 2001, terrorist attacks remains, to this day, one of the most impactful hits in franchise history.

Lesser known is what Piazza did hours later. Among those in attendance that night were Carol Gies and her three sons, whose father, Ronnie E. Gies, was a firefighter lost in the World Trade Center attacks. After the game, the Mets invited Bobby, Ronnie and Tommy Gies into the dugout, where Piazza met the teenage boys and gave them his wristbands.

“He was lost for words, like he didn’t know what he could do,” Carol Gies said.

From there was born a friendship between the Gies family and the Mets organization that remains strong to this day, 18 years after the attacks. All three Gies boys are firefighters now, just like their father. It is a prospect that both frightens their mother and fills her with pride.

“It means a lot that they’re following in their father’s footsteps. It does,” Gies said. “It scares me. … It’s terrifying, actually. It really is terrifying. But you put it on the back burner. I can’t live that way. I’ve decided I can’t live that way. I have to let them do what they want to do and couldn’t be more proud of them.”

The morning of Sept. 11, 2001, was like any other for Gies. She went for a walk with her husband in the morning, and she talked with him on the phone as he commuted to work. Then Gies went to her own job at a local daycare center, oblivious to the events taking place in Manhattan until her brother called, imploring her to turn on CNN. Even then, Gies did not consider the possibility that her husband might be in danger.

Hours later, the mood had changed, and Gies found herself crammed in her house with all three of her sons and various family friends. Gies’ husband never returned from the World Trade Center. She was grief-stricken.

But the family, like the city, had to heal. Like many family members of fallen servicemen and women, Gies found herself at Shea Stadium 10 days later, watching a game that was both frightening and inspiring for those in attendance. At one point, Braves outfielder Brian Jordan jogged over and gave her a hug. Then the Mets brought her and her boys onto the field and into the dugout, where they met Piazza.

“And it just continued over the years,” Gies said of her family’s friendship with the Mets -- particularly with vice president of alumni relations Jay Horwitz and late public relations staffer Shannon Forde. “Coming to see the Mets, we love it. We really love it.”

The Mets have remained active in their support of firehouses throughout the city, holding an event at one every September. This year, Steven Matz and Todd Frazier visited Engine 289/Ladder 138 in Corona. As usual, the Mets took batting practice on Wednesday wearing caps representing the various New York City service agencies that were at Ground Zero. The Gies boys, all now in their 30s, still attend games at Citi Field when they can.

It is a difficult time of year for them, but also one that inspires goodwill.

“I’ve lived my life and moved on,” Carol Gies said. “But still, this time of year comes around and it’s heart-wrenching. You turn on the TV and there’s all these commercials, 9/11, ‘Never forget.’ You love to see that because you don’t want them to forget, but it’s just a reminder. It’s the hurt. It’s a dreaded day. Wednesday is a dreaded day for me. The worst part for me is watching my kids go through life without their father. That’s really the hardest part for me.”