A wave of emotion swept through lower Manhattan on Sunday as thousands of veterans, their families and many of the city’s first responders retraced the steps of fallen firefighter Stephen Siller, who died in the collapse of the Twin Towers on 9/11.

“It was amazing; beautiful to see the light at the end of the tunnel,” said Army veteran Jeremy Breece, 40, of San Marcos, Texas. “You see so many people lined up with flags. I am grateful to be here,” he said after crossing the finish line of the Stephen Siller Tunnel to Towers 5K Run & Walk on Sunday morning under sunny skies and summerlike heat.

Breece pushed himself in his wheelchair through the tunnel from Brooklyn onto the West Street highway next to the World Trade Center. The event, now in its 16th year, honors Siller, 34, who lived in Rockville Centre, and who famously ran through the Brooklyn-Battery Tunnel in full gear to get to the towers that day.

More than 30,000 people from across the nation and around the world participated in the event, organized by the Stephen Siller Tunnel to Towers Foundation. This year’s event raised about $2 million, organizers said. The foundation has raised $70 million since 2001 and has built 66 homes for injured veterans.

In 2011, Breece lost both his legs when he stepped on an improvised explosive device while deployed in Afghanistan. The foundation donated a tractor to help him maintain his 5-acre property in Texas.

This was the fifth year in the event for Army Staff Sgt. Rusty Dunagan, 37, of Edmond, Oklahoma. Dunagan, an Iraq War veteran, lost both legs and his left arm in Afghanistan during his second deployment. The foundation built him a home that is wheelchair-accessible.

advertisement | advertise on newsday

Coming up behind him was 10-year-old Jack McNamara of Blue Point. He wore his father’s FDNY bumper gear as he ran through the tunnel — a run he has participated in since he was a baby, said his mother, Jennifer McNamara, 49.

His father, John F. McNamara, died at 44 of 9/11-related cancer in 2009. McNamara worked the pile after the collapse of the towers and later pushed for the James Zadroga 9/11 Health and Compensation Act.

“I’ve been speaking about 9/11 since I could talk,” said Jack, an aspiring EMT who is in the sixth grade.

He took off his father’s bumper jacket. “That’s 18 pounds,” he said with pride. He then pulled out his father’s FDNY baseball cap. “I always put this on after the run,” Jack said, reaching for his father’s helmet, cradled under his arm.

Runners are greeted by members of the FDNY after exiting the Manhattan side of the Brooklyn-Battery Tunnel during the Stephen Siller Tunnel to Towers Run on Sunday, Sept. 24, 2017. Photo Credit: Charles Eckert

“It’s amazing how he has grown,” Jack’s mother said. “He was 2 1⁄2 when his father died. I was pregnant when his father was diagnosed with colon cancer. My husband hung on as long as he could. . . . We have done a lot of good in his name and I have my kid. I am pretty lucky.”

Catherine Christman, Siller’s cousin and a spokeswoman for the foundation, said the run has come a long way since its inception.

“I was there when there were 2,000 people running and we had a sound system that didn’t work,” she said. This year there were runners from all over the world, including firefighters from Australia and London, and runners from as far away as Sweden, Indonesia and Israel.

“We take that as a sure sign that we have to actively demonstrate that good comes out of evil,” Christman said. “That speaks volumes to us.”

Hundreds of American flags lined West Street as runners made their way to the finish line. Also along the route were banners with photographs of people who died in the 2001 terror attacks.

The Tunnel to Towers run honors FDNY firefighter Stephen Siller, 34, who died on 9/11 after he ran through the Brooklyn-Battery Tunnel in full gear to reach the Twin Towers. Photo Credit: FDNY

Roy Zou, 35, a volunteer firefighter in Manhasset, ran in full gear. “Every year you want to see people doing something for the same purpose,” he said, adding that he runs every year. “It’s very impressive.”

advertisement | advertise on newsday

Conor Fitzgerald, 28, a police officer in Arlington, Virginia, who is originally from Babylon Village, said this was his fifth year running, but this year was extra special.

Hs friend and fellow Arlington officer, Harvey Snook III, 49, died of 9/11-related cancer last year after having responded at the Pentagon that day. Fitzgerald wore Snook’s photo and story on his back.

“It’s insane. It’s definitely like the public safety brotherhood,” he said about the turnout. “It’s a humbling experience.”

With Alison Fox