Kristen Hanson was the youngest victim of the September 11 attacks

Kristen Lee Hanson

Kristen Lee Hanson was the youngest victim of the September 11 attacks

Kristen Lee Hanson, the little girl who loved Mickey Mouse and made her family smile during the first hour on her first plane ride, sat with her mum and dad when her dad called his parents.

"Dad, I think we're getting kidnapped," Peter Hanson said over the phone.

It was September 11, 2001, and Peter and his wife, Sue Kim, and Kristen, too, were heading to California, where they had planned to see their relatives and go to Disneyland.

The family was on United Airlines Flight 175, the second plane to be hijacked. They were among the nearly 3,000 victims killed in terrorist attacks. Christine was the youngest victim, one of eight children killed that day.

On Wednesday, several days before the 20th anniversary of the attacks, Eunice Stylus Hanson, Kristen's grandmother, remembered her as an "extraordinary little girl."

"It bubbles. Recalling the time she was recovering from foot surgery, Kristen brought her Band-Aid, thinking it would help," Eunice told NBC News. "If I got hurt, I found a way to make everyone laugh."

Eunice spoke to Kristen two nights ago when I called her to wish the family a good trip.

Initially, the three were scheduled to travel on September 10. But they moved their ride at the last minute because Peter, a software company's vice president of sales, had a conflict at work, Eunice said. It's something that still haunts her.

"It killed me," she said. "For over a year, I couldn't talk about it."

Two decades of grief: 'I just got used to it.'

Kristen was born on February 22, 1999, and lived with her parents in Groton, Massachusetts. Eunice said she loved helping her father when he was gardening, watering plants and trees, and telling them she "feeds them."

Kristen was given her middle name after her grandfather Lee Hanson, Eunice's husband. Eunice said that she and I had a relationship since the beginning.

"I stuck with it when we went to visit," she said.

Eunice and Lee were close to their granddaughter, sometimes staying with her overnight when her parents were away. The next time they met, Kristen would be at a friend's wedding shortly after her vacation at Disney. Eunice couldn't wait for Kristen to show off her signature dancing move, with her feet tapping and her body shaking. Kristen called it "Happy Dancing."

Peter's call came on September 11 while Lee and Eunice were having breakfast at their home in Easton, Connecticut. After receiving Peter's call, Lee called the authorities, who informed him that a different plane had been destroyed at the World Trade Center in New York.

Lee and Eunice turned on the TV and watched the burning tower. When the couple tried to process what they saw, Peter called again. This time, he told me his plane was going to crash. "Don't worry," he said his father, later followed by "Oh my God! Oh my God! Oh my God!"

"The TV was on at the time, and we saw the plane crash into the second tower," Eunice said. "Lee hung up, and it was never the same."

Lee did not live to see the 9/11 defendants tried. He passed away in November 2018. At the age of 86, Eunice wasn't sure if she would do that either, especially given the many delays in the case.

Eunice said she could ask the defendants a simple question.

"After I finished swearing an oath on them," she said, "I would ask them, 'How could you have looked in the eyes of my little granddaughter and wanted to kill her?'" "How can you have so much hate?"

Today, Kristen was 22, but Eunice still views her as the energetic girl who carries a stuffed Peter rabbit with her everywhere, a beloved property that her grandparents donated to the 9/11 Memorial and Museum.

For 20 years, Eunice has been thinking about missed milestones: what could have been Kristen's first day in kindergarten, when I graduated from high school when she got her first job from college.

Eunice wonders if Kristen will follow in her mother's footsteps and follow microbiology, sales like her father, or something else entirely.