Last December, his New Jersey community was still reeling from Hurricane Sandy's effects when Adam Lanza opened fire at Sandy Hook Elementary School in Newtown, Conn., killing 26 people, 20 of them children.
"I was thinking that we could combine these tragedies to bring some time of hope and recovery," says Lavin, 55, of Woodbridge, N.J.
So he formed The Sandy Ground Project: Where Angels Play, whose goal it is to create 26 playgrounds, most in storm-ravaged areas, each dedicated to one of the 26 victims from the Sandy Hook shootings.
So far 10 playgrounds have been built and they have raised more than half of the $3 million needed.
"It's where the angels that we lost will watch over the angels we still have with us," says Lavin, a firefighter in Elizabeth, N.J.
Carlos Soto, the father of teacher Victoria Soto who passed away protecting her students at Sandy Hook, says that he finds peace when he goes to her playground in Stratford, Conn.
"When I'm having a bad day, I go sit at her playground and I feel relaxed," says Soto, 53.
The playground is pink and green, pink being her favorite color and green symbolizing Christmas.
"She loved nothing more than spending Christmas with her family and buying people gifts," he says.
Soto now finds even more peace by attending all the ceremonies of each additional playground that is built.
"I'm going to go to every single one," he says. "It helps me heal."
How It BeganBuilding playgrounds wasn’t a random thought for Lavin. It started after 9/11 when a third-grade class reached out to his squad in New Jersey.
Their captain's niece, Jackie Wintruba, was a teacher at North Bay Elementary School in Bay St. Louis, Miss. and her class wanted to send the firefighters words of encouragement.
"We spent six weeks back and forth to Ground Zero," says Lavin. "To see those cards and words of encouragement brought us some happiness during a dark time."
They took it as a nice gesture and then put it in the back of their minds – until Hurricane Katrina hit four years later.
The firefighters wondered how that class was doing and found out 80% of those students had lost their homes and their school had been destroyed.
"We went down there and they were going to school in tents and makeshift trailers," he says. "The area looked like it had happened yesterday, not six months ago."
Lavin asked them what they could do.
"They said, 'There is nothing but rubble and glass and debris and their playground was destroyed,' " Lavin says, "so they needed a playground."
They built three.
"The thing that I had learned in Mississippi was that the playground was more than just a structure for kids to play on," he says. "It was a symbol of hope."
Tammy Raymond agrees.
"Those children will never forget what Lavin did," says Raymond, 42, a teacher at North Bay Elementary School, where one of the playgrounds was built.
"He was like an angel in disguise," she says, "and it was like we had known him all our lives."
Lavin says the project helps him as well.
"To build these playgrounds and see the community come together," he says, "is the most rewarding feeling in the world."
Know a hero? Send suggestions to email@example.com. For more inspiring stories, read the latest issue of PEOPLE magazine