With memorial services taking place across the USA yesterday, it's not easy for American children born on 11th September to celebrate their birthday.
Gabrielle Wallach, from New York, told her parents she didn't want cake on her 12th birthday yesterday.
The seventh-grader said instead of celebrating with goodies she wanted to quietly honour the 2,975 people who died at the World Trade Center eight years ago.
She was four years old, and awaiting her special SpongeBob SquarePants birthday cake at her home in Manhattan, when terrorists struck in 2001.
Gabrielle's mother Dinetta remembers her daughter asking over and over again: "Why is that building burning?" Then the little girl asked: "Did my SpongeBob cake blow up, too?"
"She thought the whole city was coming down," Dinetta told ParentDishUS.
The next year Gabrielle refused to celebrate by taking cupcakes into school and wouldn't talk about her birthday in class until she was 10.
Every year the family gathers in their neighbour's apartment to watch the memorial beams of light that project into the sky where the World Trade Center once stood.
Benjamin Hesse turned eight on 11th September, 2001. As the day unfolded, it emerged that one of his uncles, a fireman, had died in the line of duty at the World Trade Center.
Unsurprisingly Benjamin didn't want to celebrate his birthday that evening. His mum Debbie has tried to make sure he does celebrate on the day and took the family out for dinner on his 16th birthday this year.
"I tell him no matter what happened, it was still one of the most important days in our life," she said. "He was too young to lose (his) birthday. Would I have changed that day? Of course."
Hillary O'Neill is proud to be born on 11th September. Her parents buy her red, white and blue balloons and place an American flag on her birthday cake.
Her mum Heather heard about the terrorist attacks in hospital, in the middle of labour.
She remembers wondering: "What am I doing bringing a child into this world when it is so evil?"
However she and her husband Glenn now see Hillary's life as a symbol of hope.
Some parents choose not to make a big deal out of the date. Joshua, from California, was born on 11th September, 2005. His mum Wendy has not mentioned the significance of the day to him.
She said: "I've never said anything to him. As your child gets older, you can talk about it. Would I necessarily talk about it on their birthday? I don't know. ... Where do you find the line to say we are going to keep living ... versus an acknowledgment of the past?"