He and a handful of others had been tackling the marathon route with the message on their green T-shirts fueling their strides.
The names of the victims were on their backs, and "Newton Strong" was covering their hearts on the front.
It was a fundraiser for the victims, with a purpose.
"To represent the kids, our town, to maintain awareness for our cause, and everything Newtown Strong stands for, to inspire change," Abrams said.
But the bombings reminded him and others that inspiring change takes time - it's not a sprint, but in fact, a marathon.
And Monday's run ended tragically, with scores injured and three dead.
"I cried again, just like I did on 12/14," Abrams said.
Thom's wife Lisa watched on TV as the scope of the attack sunk in and the names and faces of the victims were revealed.
"Just like those kids that went to school one day, to enjoy the day with their friend," Lisa Abrams said.
She sees a connection between the grief and pain that the Boston attack victims' families are feeling and says it's shared in Newtown.
"What Newtown is trying to do is spread the message," she said. "It's not just about Newtown, it's about all of us working together to create a safe community and safe country."
Laura Nowacki was one of the ones who rushed to help the shooting victims at Sandy Hook Elementary School. As a first responder, the pediatrician was stunned at the horror she encountered.
Four months later, she hurried out of Boston with her husband and four children, anxious to keep them safe after the deadly explosions near the finish line of the historic marathon she had just completed.
"That really scared us," she said. "My daughter was really upset, so we needed to be a family first and get back home."
The race was supposed to help Nowacki recover from the shock of the Newtown shootings that killed 20 children and six educators - and from which her 10-year-old daughter fled uninjured. Instead, it brought the painful memories back.
"Running has been kind of my escape, my freedom," Nowacki said. "We felt like we were getting back to normalcy. My husband said, 'Leave it all in Boston and come back to a fresh start.' And now it's just unbelievable."
Nowacki was also part of the group of eight who ran for the Newtown Strong Fund, which was set up to raise money in the wake of the shootings. She was its spokeswoman and attended a news conference in Boston last week at which marathon organizers announced they would honor the victims of the shootings with a special mile marker at the end of the 26th mile of the 26.2-mile race on Monday.
Before the race began, there were 26 seconds of silence in honor of each of the 26 victims. And each mile of the race was dedicated to one of them.
"When I ran each mile, I thought about each kid," Nowacki said. "From Charlotte Bacon on Mile 1 and all the way to Allison Wyatt at the 20th mile. Her mom cheered me on when I was running. So I feel like each mile did mean something to the families."
Each of the last six miles was run in honor of the educators who were shot.
"I felt strong coming across the line," said Nowacki, who finished the race in 3 hours, 28 minutes, 55 seconds. "I felt like I came and did what I meant to do and you heard the cheers for Newtown all the way along. It was a good thing. And then we got back to the hotel and started hearing the sirens."
David Oelberg, another Newtown Strong runner, had crossed the finish line on Boylston Street about 12 minutes earlier in his fourth Boston Marathon - a line he was thrilled to see.
"When you turn down Boylston and see that finish line, there's nothing but sheer happiness in your mind and that's forever going to be stained in mine," he said. "When I make that turn onto Boylston and see that finishing banner, I can't imagine that I'm going to have the same sheer joy ever again."
He's not even sure he'll run his "favorite race" again, fearing it might be a target for similar acts.
"I've told my kids I'm going to run a marathon when I'm 90," said Oelberg, a 49-year-old pulmonary physician at Danbury Hospital, who trained at Massachusetts General Hospital where some victims were taken Monday, "but I'd be lying if I said I'm going to be only targeting large, big-city marathons. At this point, there's something to be said for some for those smaller low-key events, too."
Despite the trauma of the past couple of days, Nowacki also plans to continue with her running and her dedication to a new cause - to help the victims of the Boston explosions cope.
"We are Newtown Strong and we want to help them be Boston Strong," she said. "We want to help with what we've learned. We want to pass on some of that."
(The Associated Press contributed to this report.)CLICK HERE TO SEE PHOTOS FROM THE SCENE OF THE BOSTON MARATHON EXPLOSIONS