PORTLAND — A group of Mainers starts work Tuesday at a summer camp in Massachusetts where they will provide comfort and support to children affected by one of the deadliest attacks on civilians in U.S. history.

America’s Camp provides a safe haven for children whose parents or siblings were killed in the Sept. 11, 2001, terrorist attacks on the World Trade Center, the Pentagon and United Airlines Flight 93, which crashed in a Pennsylvania field.

This will be the last year that the summer camp, which is located in the Berkshire mountains of Massachusetts, is held.

Allison Beck, of Portland, has been volunteering at the camp for the past eight years.

She was trained as a grief facilitator by the Center for Grieving Children in Portland.

“At first, nobody actually knew what they were doing, but it was wonderful in the sense that we wanted to provide a safe place to help these kids cope with their loss,” Beck said. “Over time, these kids learned that camp is a safe place to talk about whatever it is they need to talk about.”

America’s Camp offers traditional recreational summer camp activities. But it also provides a place for children to talk about the trauma they suffered 10 years ago.

Recognizing that it just wasn’t another summer camp, its founders decided to bring in the Center for Grieving Children to train counselors. The Portland-based organization has played a role at the camp since 2002.

Anne Lynch, executive director of the center, said a space called Buddy Central was created at the camp. It provides a place where children can go to talk about their grief.

“They wanted to take these kids away and give them a true camp experience,” Lynch said. “But their original plan was to do it for one year. I kept saying I hope you can do this for more than one year and they did.”

Children or siblings of firefighters or police officers who lost their lives in the line of duty after 9/11 may also attend the camp in Hinsdale, Mass., a small town in the Berkshires.

As the first wave of children matured, more kids came, and now many of the children who were once campers have grown up to become camp counselors.

This year, the youngest campers will be ages 7 and 8. Their parents were firefighters or police officers who died in the line of duty after the 9/11 attacks.

The 9- and 10-year-olds were in utero when their fathers died on 9/11.

About 30 teenagers, who started coming to America’s Camp as young children, will serve as counselors in training. Another 50 or so counselors started at the camp when they were in middle school or high school.

Michael Moore, of Cape Elizabeth, plans to volunteer at America’s Camp for a second consecutive year. He also serves on the Center for Grieving Children’s board of directors.

Moore views his role as being more of a good listener — he likes to call himself a “buddy” — than a grief facilitator. He and other facilitators try to make the camp as welcoming as possible.

He said many of the children still talk about that day in 2001 and how it affected their lives.

Lynch, who was at the camp during its first year, remembers the night that campers and counselors — who came from around the world — gathered around a bonfire.

The counselors stood while holding their country’s flag. It was a moving moment, Lynch recalled.

“It felt like the world was holding these children in their hands,” Lynch said.

As the decade since the attacks draws to a close, Beck says she will miss seeing the five girls, who were ages 11 to 13 at the time, who she started camp with. Each girl lost a father in the 9/11 attacks. Most were firefighters or police officers. The girls are young women now, and have become camp counselors.

“At first they didn’t want to talk (about their grief), but they’ve grown into amazing young women,” Beck said. “I hope I’ve had a small effect on their ability to share what happened 10 years ago.”