Andrea Pierce of Camden hoped when she first heard the loud explosion near the finish line at the Boston Marathon that it was a celebratory cannon firing or perhaps an accidental explosion from a leaking gas line. When the second explosion came seconds later, she realized it was an attack.

Pierce, who works in the office at the Camden-Rockport Middle School, was about 25 feet away from the first bomb that went off, waiting with two of her children to watch her sister-in-law cross the finish line.

"When the blast hit, to my left, I looked up and saw smoke," she said. "I heard glass tinkling, falling like rain."

They were on the same side of the street where the first explosion took place, in an area where a number of flags from around the world were lined up. Standing with Pierce was her son, Kevin, 20, and her daughter, Claire, 13.

They had attended the marathon on Patriots Day, April 15, in Boston when the bombings occurred. The Pierce family often attends the marathon and other Boston events. Andrea went to Boston University and family members in the Boston area often run in the race.

Both her son and daughter have had ringing in their ears and pain caused by the noise from the blasts.

"It was incredibly loud," she said. "…That's what we remember most, the sound and the running."

In the moments after the bombing, Pierce believes her son witnessed some of the devastating injuries at the scene, but said he is not ready to talk about this.

"I remember some man's voice saying, 'Move! Move! Run! Run!'" Pierce said.

Due to the barricades separating the spectators on the sidewalks from the street, they had limited options of where to run. They began to move as fast as they could with the crowd of people running from the scene.

"To our left was a bomb site. To the right, we could kind of run down the street," she said. "But you just hoped and prayed that was the direction of safety. …Not knowing if at that next corner there would be another explosion."

The family had gone to Boston on a bus to avoid paying for parking and getting caught in traffic, so they were now stranded with no transportation out of the city. They could try to go to South Station to start the journey home, but Pierce did not want to go back through the downtown area that had dissolved into chaos following the explosions. So they walked away from the city toward Cambridge, hoping to meet back up with her brother and sister-in-law.

At first, she was not even sure her other family members were OK. She knew her brother and his 5-year-old twin sons were supposed to be near the finish line and that her sister-in-law had passed the last mile marker to approach the finish line as the bombs went off.

"So the whole time we're running and escaping, we feel like we have to check on them too."

She was able to check in on most of her family members via cell phone before the reception was shut down. It took about a half hour to find out if her brother's family was safe.

The three Pierces continued to move away from the scene and came to the bridge at the Charles River going into Cambridge.

"And my mind was thinking of the pictures I saw of 9/11, all the the people walking across the bridges to get back to their boroughs," she said. "A lot of the activity that we were taking on felt like that."

Many of the people walking with them were talking on cell phones, crying and shaking.

For Pierce this was immediately reminiscent of the terrorist attacks of Sept. 11, 2001. Her 13-year-old daughter was 2 years old at the time of those attacks and had experienced the event only as history. For her, the perspective was different.

"I think if 9/11 had never happened, or subsequent terrorist things, or school shootings, or all of those things that have come into our lives, maybe we would have all stood around and watched the fire trucks come or something," she said.

Instead, the event had a terrible familiarity.

They took a rest in a park and were surprised to see other people out enjoying the day as if nothing had happened. People were talking on their phones and jogging. Some of those people had not heard about the bombing yet.

"You kind of wanted to say, 'Hey, I've just been bombed!'" she said.

One woman stopped and asked if they were OK, if they had a place to go, or needed anything. Pierce said a moment of simple kindness stands out at a time when the family was feeling stranded.

Her husband, Dr. Brian Pierce of Midcoast Medicine, was driving down from Maine to pick them up, but they had hours to kill.

While all of this was going on, her sister-in-law, having been diverted from the race, which had now been shut down, ended up at a Lutheran Church where she was provided with a coat to keep warm and something to eat and drink. Pierce's brother and his 5-year-olds were taken to a large truck trailer by a friend who was an official in the race. There, scanners and radios were providing information about the horrific unfolding events, which her brother had to try to shield the young children from as much as possible.

Coming home to Maine, her family watched the massive manhunt unfold on the news. Bombing suspect Dzhokhar Tsarnaev was captured April 19 in Watertown, Mass. His brother, Tamerlan Tsarnaev, 26, was killed after a chase and firefight with police.

To some extent, the speed with which authorities closed in on the suspects offered a sense of closure for Pierce. She said she looks forward to finding out more about why they did this.

It has also helped them to get back to school and work and their routines.

She acknowledged that some members of the family have had nightmares following the incident.

"There's sort of been an injury to our family," she said. "I guess we can say we've been attacked. Someone was planning to kill  — not me, Andrea, but whoever was in that spot, whoever happened to be in that spot. I happened to be far enough away that I didn't become a number, or a casualty."

After witnessing the event, she said the "what if" questions haunt her. What if she had stood in a different place?

"And you can feel a little bad that, how did I get so lucky?" she said.

She said they think a lot about the families who were not lucky, who lost loved ones or suffered injuries. Killed in the attacks were Martin Richard, 8; Krystle Campbell, 29; and Lu Lingzi, 23.

Pierce said she will go back to Boston to enjoy events there including the marathon.

"I don't know if we'll stand right on Boylston Street (near the finish line)," she said. "Not because I think anyone would re-attack that space, but I think the good feeling will be gone. There will be bomb-sniffing dogs and police… there will be a presence so people will feel safe and I appreciate that, but that won't be my memory of the day we were having. The fun will be gone for me."

Instead, she said she may go to a cousin's home near the 11-mile mark or to Heartbreak Hill.

Courier Publications News Editor Daniel Dunkle can be reached at ddunkle@courierpublicationsllc.com or 594-4401.