9/11 ceremony live updates: Families gather at WTC, Pentagon, Shanksville to mark 25 years

Former ABC News correspondent Ann Compton recalled being in the Florida classroom with former President George W. Bush when the Twin Towers were attacked and the frantic flight with White House staff and other reporters to safety.

"The Secret Service wanted him out of there," Compton, who was the press pool reporter that day, said of Bush. "He made a quick statement. We raced to the airport. Air Force One at that point when we reached the airport in Sarasota, the engines were roaring."

MORE | Students with President George W. Bush on 9/11 reflect on the day: 'You could see it on his face'

Air Force One was scheduled to fly back to the White House immediately but during the flight the Pentagon was attacked, she recalled.

During this time in the air, reporters had limited communications but were able to watch news feeds from the jet's TVs. It was there they saw the towers fall.

"It was horrifying. I didn't worry about Air Force One or our safety, I worried about what 20, 30,000 people in those skyscrapers, and we were watching them fall to their death," she said.

Nearly 3,000 folding chairs lined Bryant Park on Friday as part of a public memorial honoring those lost in the Sept. 11 attacks.

Each of the 2,753 chairs represented a person killed on 9/11 and was arranged facing south toward the Twin Towers that once stood in Lower Manhattan. The installation was open to the public, with visitors invited to take a flower and leave a note on a chair.

Michelle Charlesworth has the details from Bryant Park.

"It's so compelling, it's so hard, but you know they didn't win. We are still here," one visitor said while reflecting on the memorial.

Dan Biederman, founder of the Bryant Park Corporation, said members of the public were encouraged to participate in the tribute by leaving a flower or note on each of the chairs.

As visitors moved among the rows of chairs, many paused to reflect, pray and leave messages in remembrance of those lost on Sept. 11.

People moved out of the way on Friday in the Oculus as sunlight reflected the outline of the Twin Towers on the floor.

This is the result of an architectural feature that moves the light across the floor during the exact time of the attacks - from 8:46 a.m. to 10:28 a.m.

The design was conceptualized by master plan architect Daniel Libeskind, who took inspiration from commemorative sundials, embracing the meaningful relationship between light, remembrance, and the city around the campus.

"Permanently weaving that wedge of light into the literal foundation of the Oculus is a fitting tribute to the memory of those first moments of the attacks and to the master design vision that our redeveloped campus is built around," said Port Authority Chairman Kevin O'Toole. "Future generations will be able to follow the path of the wedge of light across the campus using these markings to connect with how the events of that day and those terrible moments in time are with us still, woven into the campus itself."

The reading of the names at the New York City ceremony concluded with powerful words from the son of victim Michael Massaroli.

"You do my dad's legacy and the legacy of all these victims no honor by using this tragedy to spread hate," he said.

"We have seen a medley of people come up today (to read victims' names), of all races, all religions, all creeds," he said.

"I've had to grow up and spend the past 25 years seeing people use (9/11) to hate on our Muslim brothers and sisters, to hate on people who don't look like them. And that's wrong and that does no honor to the victims here," he said, as the crowd applauded. "I want to use the little platform I have to ask for that to please stop."

He also thanked the dignitaries and families who stayed until the end of the reading of the names, saying every single name matters.