(CNN) -- Colin Ryan was attending his second day of high school on September 11, 2001, when an airplane crashed into the World Trade Center's north tower.
Ryan, then 14, received a note in school saying his father, John, who worked on the 89th floor of the south tower, had called his wife to say he was safe. Fifteen minutes later, United Airlines Flight 175 crashed into the south tower.
John Ryan of West Windsor, New Jersey, left behind a wife of 20 years and three teenage children, all grieving their sudden loss in their own ways. Colin Ryan, now 24 and a screenwriter in Los Angeles, was one about 3,000 children who lost a parent on September 11.
"After my father was killed, I spent a lot of time focused on school and sports, but what I remember most is the time I spent with a few close friends," said Ryan, who has written about the anniversary.
"We didn't talk much about what happened, and in fact we didn't do much at all aside from skating, driving around, watching movies and otherwise goofing around. But it was important for me to feel like a typical kid, especially with the highly public nature of my father's death."
While most children won't lose a family member in such a public attack, childhood loss is fairly common. More than one in seven young Americans lose a parent or sibling before age 20, and the emotional and financial upheaval on their lives can be severe, according to the National Alliance for Grieving Children.
Parents who have lost a loved one report that the loss is overwhelming and that there aren't enough resources to help grieving parents or children, according to preliminary results from a new survey conducted by the New York Life Foundation and the National Alliance for Grieving Children.
The parents with children at home who lost a spouse or partner within the last 10 years report the following:
78% say they think about their deceased spouse or partner every day.
91% say the death of their spouse or partner is the worst thing that has ever happened to them.
77% say it's incredibly hard to know the difference between "normal" kid behavior and grief-related behavior.
78% say there aren't enough resources to help kids who have lost their parents.
76% say they believe there are not enough resources for the surviving parents.
More needs to be done to help surviving parents and their children deal with grief, according to Chris Park, president of the New York Life Foundation.
"We can't eliminate the grief journey, but it's clear that there are all sorts of things, big and small, that we can do to make the path more manageable," Park said.
"Perhaps the number one thing we can do is just to be there for them. When we asked parents what grief resource would be most valuable, greater societal understanding was their number one response. And don't be afraid to engage. Better than three in five of the parents in our survey strongly agreed that it's better to say something and risk upsetting them than to ignore their loss altogether."
Surviving parents usually need practical help. Family and friends were key to helping Colin Ryan's family navigate the difficult days and months after 9/11.
"My mom was fortunate enough to have a lot of family, neighbors and close friends cycling in to help her with all the practical stuff --cooking, cleaning, rides home from school," Ryan said.
"It gave her room to focus on adjusting not just to the loss of her husband, but also to a whole host of new responsibilities, both immediate (memorial services) and ongoing (taking over our family finances, dealing with insurance agencies, government officials, activists, my dad's company). Suddenly, she had to develop a lot of new skills, and having so many people willing to help with everything else was crucial."
Children also need to express their grief and will often turn to art, make-believe play or stories to share their feelings. Many children who lost parents on 9/11 connected with each other through the "Art for Heart" project in Manhattan, organized by then-16-year-old Ali Millard, who lost her stepfather, Neil Levin.
That art and other children's pieces have been collected into "Art for Heart: Remembering 9/11," a book of children's art and writing being sold to raise money for the National September 11 Memorial and Museum.
"Ali designed this program so that other kids could come together as an artistic community," said Christy Ferer, Ali's mother, special assistant/liaison to September 11 families for New York Mayor Michael Bloomberg and board member of the September 11 museum. "Kids who had never done any 9/11 events before this one identified with one another. They wanted to commune with others like them."
After Long Island resident Megan Greene lost her aunt, Lorraine Mary Greene Lee, in the 9/11 attacks, her fifth-grade teacher asked the class to create drawings or poems about someone who had inspired them and their feelings regarding 9/11. Megan wrote a poem about her aunt, which appears in "Art for Heart."
"It was an outlet to get my emotions out," said Greene, now a 20-year-old college student in Belford, New Jersey. "Now I think 'Art for Heart' will give people an understanding of what kids felt about 9/11. It'll show what younger kids of different ages felt about it."
In some ways, the tragedy of 9/11 allowed grief counselors to see what would happen when they had enough resources to help families through the grieving process, said Joe Primo, associate executive director of Good Grief, a grief support center in Morristown, New Jersey. Good Grief helped "probably a half-dozen families" after 9/11. While families typically use the center's resources for about 14 months, the 9/11 children often stayed for just three to six months.
That's partly because many people got the grief counseling they needed. After September 11, New York City launched Project Liberty, the largest disaster-related public mental health project in the history of this country, to provide free and anonymous counseling to New Yorkers affected by 9/11, through September 2005. More than 500,000 people, including victims' families, received counseling. The Department of Health launched an additional 9/11 mental health program through the American Red Cross in 2008. Children of the 9/11 victims were a special priority, according to the health department.
"The [kids coming to Good Grief] had developed some pretty good coping skills, because after 9/11 was one of the only times our society dedicated adequate resources to [dealing with childhood loss]," Primo said. "The children had their needs met. They were heard, they had caring adults in their lives and they had good support. They could name what they were experiencing."
A more typical loss isn't covered by the evening news or honored every year in televised ceremonies. Often, children come into Good Grief five years after losing a parent with behavior issues, mostly because they haven't had a place to deal with the loss. "The school may be sensitive at first, but it's been six months, do your homework already," Primo said. "They're not informed to provide support. The grief experience is unique to every individual, and schools need to be flexible."
Children don't just "get over it." No matter how long it's been since the loss, a child still needs family and friends to listen, create a sense of love and security around the children and, most of all, to be patient. (You can find "Ten Ways to Help Grieving Children" and "10 Things Grieving Children Want You to Know.")
Grief is a process that can continue for the rest of a child's life, according to a 2010 Comfort Zone Camp survey of adults ages 25 and older. More than half would trade a year of their life for one more day with their departed parent, and 73% believe their life would have been "much better" if their parent hadn't died so young.
Grief often comes out at key events like graduations and birthdays, and eventually weddings and births. But grief can also appear at seemingly ordinary times, such as when the dead parent had provided help on math homework or a ride to ballet rehearsal. It can also come out at times when the parent had rarely showed up, like a Girl Scout meeting, reminding the child that the parent will never have a chance to be there.
It's important for the surviving relatives to give voice to the grief and allow the children to still know their lost parent. Colleen Fee, who lost her husband, David Miller, in a drunk driving accident several weeks after giving birth to their second son, wanted her children to someday know what an amazing person their father had been. So the Moorestown, New Jersey, resident asked friends and relatives to keep her husband's memory alive for her and the kids through letters, and she received hundreds of letters.
"The letters I received told stories of how David had helped, supported, amused or educated countless numbers of people," said Fee, who has remarried to a widower who has a son. "They gave me something to show Jack and Jonah when they were old enough. They showed [her sons Jack, now 12, and Jonah, 10] that their dad was a great guy and provided insight into parts of his personality and history that I couldn't have. It's been a way for us to talk about their dad and how they are like him, or what they would have enjoyed about him."
"Childhood grief is a lifelong experience, not a problem we're attempting to solve for children," said Andy McNiel, president of the National Alliance of Grieving Children board of directors and executive director of the Amelia Center, a grief support center in Birmingham, Alabama.
"We want to help them find support and understanding and maybe some education about what is happening in their lives. They're already going through normal childhood development, and now they have this new experience that they have to adapt to their world."
The family of Hayley Morris of Kinnelon, New Jersey, might be a case study in handling grief. Only 5 years old on September 11, 2001, Hayley remembers her father reassuring her about going to kindergarten on that day -- hours before he was killed in the World Trade Center attacks. After her father, Seth, a managing director at Cantor Fitzgerald, died, she continued to draw her entire family because "it was so nice to see us all together as a family."
Now 15 and a sophomore in high school, Hayley says her mother, Lynn, and the rest of the family surrounded her and her two siblings after the attack "all the time" to make them feel safe. Her mother's "open ears" were key to her dealing with her grief, she said. To this day, Hayley says her mother is still willing to listen anytime she or her two siblings want to talk about their father.
"We talk about him every single day, and he's always on our minds," said Hayley, whose note for her father appears in "Art for Heart." "We love him."
And yet she looks to the future, hoping the book will put a face to the tragedy and help prevent history from repeating itself. As for her, she advises people who suffer a great loss like hers not to let the tragedy define their lives.
"When my dad died, I didn't die with him," she said. "My life needed to go on."
Katia Hetter covered the September 11 attacks and the redevelopment of ground zero for more than two years as a reporter for Long Island-based Newsday.