CNN worked with Tuesday’s Children, an organization formed after the 9/11 terrorist attacks, to interview and survey dozens of teens and young adults who lost a parent that day, including a teen who was too young to have memories of her police officer father. "The 9/11 children: What can they teach us?" contains excerpts from those interviews, edited for length and clarity.

"It hurts me that my father saved many people but couldn’t save himself in the end," says Amanda Stuart, 15. Her father, Walwyn Stuart Jr., 28, was a Port Authority police officer. He evacuated the PATH station at the World Trade Center before joining the rescue effort in the north tower, reports CNN .

"I try to make decisions every day such as volunteering and giving back because I know my father would have wanted me to do that," Stuart says. "I want to live up to the amazing legacy he left to me. I want to serve others just as he did right up to his death. I want to make a difference in this world just like my father did."

She says it's been difficult growing up without a father, and that when people find out how her father died they become uncomfortable and don't know how to act around her. But she's determined to be her own person. "If you’ve lost someone to terrorism, I would say don’t let it define you. Make choices that help you define who you are going to be in later life," Stuart says.

"When my mom gets down at times, I try to cheer her up. I tell her, ‘Mom, Dad’s purpose has already been fulfilled.’ She asks me, 'What was his purpose?' I say, 'He was here to save people's lives on 9/11 – and to have me.'"