HBO's documentary "One Last Hug (and a Few Smooches) Three Days at Grief Camp" is heartbreaking, tear-jerking, and completely necessary. The film, that airs tonight at 8 pm est/pst on HBO, features the work of the The Moyer Foundation -- a non-profit organization established by World-Series champion and All-Star pitcher Jamie Moyer and his wife, Karen, and ChristianWorks for Children. Their mission is to help bereaved children who are dealing with the death of a loved one.

One in seven children deal with the loss of a loved one by the age 20, according to the movie's website. None is ready for the loss, but all who experience the tragedy, for whatever reason or cause, are called to cope in some way or another.

The documentary is shot on location at Our House of Grief Support Center, one of the free bereavement camps that is part of The Moyer Foundation's Camp Erin Network.

The 'stars' of the film are the little ones who are hurting after losing someone close; the little ones that find a connection with one another through their grief and pain.

Moyer, who pitched for the Philadelphia Phillies, Seattle Mariners, Boston Red Sox, Chicago Cubs, St. Louis Cardinals, Texas Rangers, Colorado Rockies, and Baltimore Orioles, started the foundation with Karen in 2000.

"The name Erin came from a girl my wife and I befriended who eventually passed away," Moyer says. "Erin taught us about life. She taught us a lot about grief."

Erin Metcalf developed liver cancer at the age of 15 and died two years later. The Moyers and the Metcalfs became close, and Jamie and Karen were moved by Young Erin's tender and loving spirit.

The Moyers met Erin through the Make-A-Wish foundation and they sponsored the first camp session in her honor in 2002, when she died. That year they had 42 campers attend their first session. Today, Camp Erin is held at 41 different venues, in 21 different states, with close to 3,000 kids coming to camp to heal and grow. According to the Moyer Foundation website, its the largest network of free bereavement camps in the country for children and teens who are grieving a significant loss.

"My parents' generation really didn't talk about these kinds of things," Moyer says. "When I was a young kid, if people passed away you went to a funeral home, paid respects, spent time with family members, people talked about the person who passed away and that was it. Then you came home and put it in the closet and didn't really talk about it. For those who have strong emotional feelings that grief builds up."

Moyer points out that when children are dealing with a loss of a parent or a brother or sister, they have nowhere to go once they return to their normal lives. In school they feel like outsiders because they've lost someone so close. They think they're different. Sometimes they fall out of friendships that they used to have or they lose interest in the things they enjoy. Grief can become overwhelming.

From profound sadness to unbearable confusion and anger, a child's grief can be devastating. It can also be terribly lonely for the young sufferer. At a time in life when fitting in is important, grief can make kids feel different and isolated from their others.

At Camp Erin, children are comforted knowing that there are other children who have had similar grief and loss experiences and feelings. Campers have an opportunity to tell their story, express their feelings and memorialize their loved ones. They are provided with the tools and resources needed during and after camp, including memories and friendships that last long after camp is complete.

"Every one of these kids fills my heart, and I'm thrilled that these camps exist for them," Karen Moyer, a mother of eight, told the Rancho Santa Fe Review. "These kids come together and they find positive ways to cope. It truly allows them to live on and live well."

The Moyers are in hopes that many will watch the documentary and be touched by the children the way they were. So many people deal with this issue, and so few know how to respond in a healthy way.

'One Last Hug', and Camp Erin, hope to change that.