LEWISTON — Paula Rousseau’s first Boston Marathon was everything she had dreamed and more.

Then, 20 minutes after crossing the finish line, the Lewiston woman heard the first explosion.

Sitting in an alley about a block away with her running partner Barbie Clement, Rousseau initially thought maybe it was a part of the historic race’s regular festivities.

“I looked out from behind a partition and I could see the smoke,” Rousseau said.”I just thought it was a celebration. But then I said to Barbie, ‘I don’t know, with this smoke. That doesn’t seem like a celebration.’ And then the other one went off within a few seconds. So then we realized something wasn’t right.”

Amidst the confusion near the finish line, Rousseau, a second-grade teacher in the Auburn school system, dug her cell phone out of her bag and saw numerous calls and text messages from family within the city. She couldn’t respond because cell service had been shut down.

Rousseau and Clement eventually got back to their hotel outside the city and were able to contact relatives, although it took about three hours before anyone could reach Rousseau’s husband, Mick, who was still in the city, to let him know she was fine.

“I couldn’t be in shock yet, because I wasn’t sure about what was happening,” she said. “About an hour after we were walking, Barbie started getting images from her sister-in-law on her iPhone. When we saw that, we were choked up pretty severely. That’s when it hit us.”

Rousseau said it took her a month or two to get over the shock of what happened and her proximity to it. But she’s been determined to return to the marathon ever since.

“They tampered with the wrong community,” Rousseau said. “We’re runners, and runners are tough. We’re determined. We have strong willpower, and it’s a positive atmosphere that we surround ourselves with when we’re running.”

Rousseau is part of PR Racing, a running club that meets weekly at Bates College to create that positive atmosphere and train together. She is among about 10 runners from the club who will be running in the 118th Boston Marathon on Monday.

The group includes Boston Marathon veterans and first-timers. While all have their own personal reasons for wanting to run this year, all agree that this marathon will be different from any other.

The most common belief among the runners is that they will be making a defiant statement to the terrorists who last year set off the bombs that killed three spectators and injured 264 others.

“No matter what you do, you’ll never ruin our spirit, you’ll never bring us down, because love always prevails,” said Christie Tebbets, a 44-year-old personal trainer from Lisbon who will be running Boston for the first time.

“It’s a day of triumph, I think,” she added.

It will be a stark contrast to the feeling of helplessness many of them had last year, even as they watched the events unfold from hundreds of miles away.

Last Patriot’s Day, Steve McCarthy, an assistant track and field coach for Lewiston High School, was at practice when head coach T.J. Niles told him a bomb exploded at the finish line.

McCarthy’s brother, Eric, was running the marathon, and the news made Steve’s heart drop.

“All I could think about for the next couple of hours … I didn’t know if my brother was safe. I didn’t know if my brother was alive. That’s the worst possible feeling in the world, to not know,” he said.

A few agonizing hours later, McCarthy found out his brother had called their mother to let her know he was safe.

A 27-year-old ed tech from Lewiston, McCarthy said he regrets not entering last year’s marathon (when it came time to register, he didn’t know where he was going to be living last April). He would have entered to run again this year regardless, “but because it happened, it adds an extra motivation,” he said. “This is the one I’ve been training for the entire year.”

Brother and sister Thomas Bennett and Kelly Brown planned to run Boston this year to celebrate the anniversary of the first marathon they ran, the Maine Coast Marathon.

“Next month will be our 30th anniversary of our first marathon. I think when the events happened in Boston we both decided we wanted to be there this year,” said Bennett, who will be running his sixth Boston but his first since 1995.

Brown watched last year’s race from mile 22 with her husband, Scott.

“We were heading back to our hotel, walking along the barricades, and all of a sudden the cop tears it open and cops just started screaming through. He told us what happened,” said Brown, a 50-year-old Westbrook school teacher from Lewiston who will be running in her third Boston.

Scott Brown, the founder of PR Racing, coached a half-dozen runners in last year’s marathon, and the couple spent hours frantically trying to make contact with them.

“It was kind of scary because we couldn’t get in touch with them,” Kelly Brown said. “We were scared because we didn’t hear from Peter Rearick for, like, hours, not knowing that he was stopped before the finish.”

Bennett said he isn’t surprised a reported 36,000 runners will participate in Monday’s marathon, the race’s largest field ever aside from the 100th marathon.

“I think people are just trying to reaffirm the status of the Boston Marathon as a celebration rather than remembering it for what happened last year, and not letting the act of two individuals destroy this historic tradition that goes back 118 years,” said Bennett, a 57-year-old library director from Auburn.

The runners said security is the least of their concerns on Monday. They’re all encouraging family and friends to go to Boston and cheer them on.

Rousseau said she’s more nervous about the crowded running field.

“It’s a hard race to PR, but it might be really hard to this year because of the crowds, too.” she said.

Some are prepared to set aside personal times for one marathon and just live in the moment.

“If I ran a six-hour marathon at this Boston … please God, just let me enjoy this experience. Because it is a moment in history,” Tebbets said.

The PR Racing contingent, which also includes Beryle Martin, Vicki Waterman, Peter Rearick, Dan Works and Steve Bang, know the eyes of the racing world will be on Boston on Monday. But ultimately, competing in the marathon is a personal journey, they said.

“The Boston Marathon has had such a powerful emotional aspect for me,” said McCarthy, who will be running his fourth Boston. “Every single year there’s something really powerful about it, good or bad. It brings out the strongest emotions in you.”

“The first year I did it, I suffered through the last eight miles,” he said. “It got so bad that my dad was standing there at the finish line and I don’t know if he’ll go and watch the Boston again because he didn’t want to watch his kid suffer that much.”

His last Boston, the 2012 race best remembered for the scorching heat that knocked out many runners, McCarthy ended up in the hospital after crossing the finish line.

But McCarthy chooses to remember the 2010 race and use it for inspiration. He was in college and battling depression at the time and didn’t think he was in good enough shape to run well.

“I ended up having the best race of my life,” he said. “And I actually have a tattoo of the Boston Marathon, and a couple of my friends that got me to the starting line, I have them tattooed on my shoulder. It’s such a significant event to me.”

The 118th Boston Marathon will combine the personal and shared significance of the event in ways few would have imagined one year ago, and redefine the rallying cry that was born then, “Boston Strong.”

“I absolutely want to finish the race, but whatever happens, it’s about all the victims and their families and what they went through last year,” McCarthy said. “It’s about us runners and our families and the entire country coming together for one day and showing that those two guys didn’t win. They’re not going to take away the event that brings out so much good in so many people.”

Local runners competing in Monday’s Boston Marathon:

Auburn: Steven Bang, Thomas Bennett, Marty Doherty, Beryle Martin, Ryan Metivier.

Bethel: Kristin Dacko.

Dixfield: Nick Young.

Gray: Barry Fifield.

Greene: Steven McCarthy, Dan Works.

Hebron: Peter Rearick.

Kents Hill: Nancy Feeney, Michael Toomey.

Lewiston: Kelly Brown, Julia Gibson, Paula Rousseau.

Lisbon: Christie Tebbets.

Monmouth: Mark Bonderud.

New Gloucester: Becky Woods.

Otisfield: Jennifer Blastow.

Pownal: David Edwards.

Sabattus: Vicki Bryant.

Turner: Ryan Fitzsimons.

Wilton: Rebecca Lancaster.