"My husband and I, we felt we had to get our family out of there, and we did," Nowacki said, fleeing before the city was locked down.

"While we were making this decision, they had said that there was a third bomb at the library … so it started getting really scary: What's the next target?" she said.

The thoughts do not always stop when the trauma has ended. Many people who experienced the bomb blasts at the marathon have reported nightmares and troubled, or interrupted sleep. Hughes is among them. She said she had a dream that she was running near the bomb as it detonated and another that the bomber was chasing her.

In her waking life, she believes in perseverance.

"People will come together," Hughes said. "We're not going to go hide, but we're going to be cautious. We're going to be cognizant. We're going to think about it. We're going to be aware."

Nowacki agrees. She believes the Boston Marathon bombings made her resolve stronger.

"Number one, it's to protect my children and show them," Nowacki said. "And I remember saying that to them right afterward when each of them were crying. Even my 16-year-old, [who] is so amazing, she's so strong. And I remember hugging her and said, 'You can, you will make a difference in this world.' And she gets it. And she's the most amazing kid. She's a leader. So, I know that she is going to do great things and leave this world a better place. And I feel like we all have that responsibility if we can."

Nowacki says she certainly will run again next year, and her resolve is echoed by others.

Another marathoner and Sandy Hook resident, David Hagerman, finished the race before the bombs exploded. The 46-year-old operations executive at IBM was on a train from Copley Square to Revere, Mass., when the first bomb went off. He got a call from a friend.

Hagerman's wife and his 14-year-old daughter, Sydney, were waiting for him at his hotel in Revere. They watched the news before deciding to get out of the Boston metro area because of the uncertainty of another attack.

Both 9/11 and the Boston Marathon bombings brought a feeling of survival first — getting out of the way of whatever might be the next target. That was followed by anger, Hagerman said. There's anger that someone stole the positive mood of the day, anger that terror kept people from wanting to go to public events and anger that society copes with body scanners and security measures because of the actions of a few people with nefarious intent.

"I was truly moved by the people of Boston as I was running, and they saw my shirt with Sandy Hook," Hagerman said. "And you could just see it in their face, the positive spirit of humanity and their support of what I represented, who I was running for, and then just the thrill of finishing a marathon … to, instantly, this fear and somebody ruined this day."

Newtown is different. Newton has brought a grief that is enduring and ubiquitous, particularly for people who live there, Hagerman and others have said. There also is an emotional chasm between a person whose family member was killed on Dec. 14 and a person who was not at the school that day — even though Hagerman lives less than a mile from Sandy Hook Elementary.

"There's no playbook for [this that tells you] here's they way you're supposed to respond. Here's the way you're supposed to talk to your neighbors," Hagerman said. "There's probably some survivor guilt that goes on in our town, too. So, you have these 26 families and maybe even some of the first responder families that are going through just a terrible time. And I'll tell you, in my opinion, the real answer is, people aren't doing well."

After the Boston Marathon, Hagerman's daughter had a panic attack on the ride back from Boston — a feeling of nausea that her father could have been among the victims.

"She actually told me that night, because she couldn't sleep, she said, 'This is different from Newtown,'" Hagerman said, adding, "When we were back at the hotel, she saw the images on TV of the blood, just horrific stuff. And she said, 'At least with Newtown, I know it happened and how terrible it is, but there wasn't the images.'"

Blood on the street, real-time panic in the faces of runners on TV were too much for Sydney to bear, knowing that her father had just been there, Hagerman said.

For Hagerman, the sentiment has turned to the familiar resolve that many Americans came to know after Sept. 11th.

"I don't want these guys to win, being very candid with you," Hagerman said. "And I've already made the decision, I told my wife in the car, because my time qualifies me for next year, I said, 'I'm going back.'"