“I’m more reflecting on what I missed out on, versus the rest of my family, who’s thinking about who they lost," Phelan Halloran says.

Phelan is her father Vincent Halloran’s final gift. She was born on May 17th 2002. That was her parents' wedding anniversary. It was also more than eight months after her father, a Fire Department lieutenant, died in the World Trade Center on Sept. 11th.

“I really do think about how my life would be different if he were around and how he would interact with me. And how my personality would be different because I think a lot of…a lot of my personality is based around this thing that happened,” she says.

Now a senior at the Convent of the Sacred Heart High School, on the Upper East Side, Phelan is one of the more than 100 children born after their fathers died in the terrorist attack. Between now and June, they will turn 18, officially leaving childhood and becoming adults.

Joseph Jones is another. “I was born into it, that’s just kind of how it is,” he says. His older siblings, he adds, “They had to deal with it and go through it.”

Joseph says the toll of Sept. 11th is a bigger burden on them because they remember their father, Arthur Jones, a steel trader at Carr Futures. He was one of 69 employees of the firm who died that day.

“He loved sports and…big family man. A lot of people always tell me, ‘Oh your dad was so this and that.’ All these good things. People I don’t even know. It’s like a good feeling,” Joseph says.

Tuesday’s Children, an organization formed to support the boys and girls who lost parents on Sept. 11th, also turns 18 this year.

Executive Director Terry Sears says many of the children have found strength in numbers, knowing they’re not alone.

“It’s hard I think for the children who don’t have memories…or have memories that are fading. They want to know…they want to understand that person is that they lost,” Sears says.

Now that they are on the verge of adulthood and preparing to leave home, the 9/11 babies are a living symbol of just how much time has passed since that day. A day when they were not yet born, but one that profoundly affects their lives.