Lauren Catuzzi Grandcolas had attended a funeral in New Jersey and was returning to her home in California when her flight was hijacked by terrorists. She was pregnant when she died.
Her family gathered this weekend on the 10th anniversary of the tragedy at the new United Flight 93 national memorial in Shanksville, Pennsylvania. That memorial opened to the public Monday.
Grandcolas was the middle sister in her family. When it comes to big sisters, Vaughn Lohec says she couldn't have asked for a better one.
"[She was] an amazing person, an angel to me," Lohec said of her sister. "She was the life of the party, probably the most mischievous of the three of us."
Grandcolas was the aunt who nieces and nephews loved and the friend who everyone wanted to have.
"She was good at giving advice," Lohec said.
Always one to face life's fears and encourage others to live life to the fullest, Grandcolas was working on a book when she died -- a guide for adults based on a merit badge system.
Her sisters knew about the project.
"She said, 'Why not have a girl scout manual or book for adult women?' I remember sitting there with her and I said, 'Lauren, I love that idea,'" Lohec said.
Lohec and their oldest sister made it their mission to finish her work.
They started by going through some of the chapters and badges with challenges she'd already outlined.
"Walking on fire was one. It's probably the most outrageous badge we have in the book," Lohec said.
From becoming a teacher to skydiving to recording music, the book challenges women and encourages them to pursue their dreams no matter what their age is.
"What I love about the book and -- again, giving it more meaning -- is Lauren's voice lives on," Lohec said. "You know, the book is titled You Can Do It, and I think the message turned into 'you should do it' because life can be short."
While Grandcolas' sisters and family have missed her every day for the past 10 years, they say her death has taught them so much about life.
"I am stronger, bigger, and better than I ever was," Lohec said. "I am exactly who Lauren would have wanted me to be."
So far, the book has sold about 200,000 copies. Proceeds from the sale of the book go to the Lauren Catuzzi Grandcolas Foundation, which was set up by her parents in her memory.
