Biden visits all three attack sites on 20th anniversary of 9/11

In the first of his wordless tributes, Biden stood in somber silence with former Presidents Barack Obama and Bill Clinton at the New York City site where planes brought down the World Trade Center's twin towers.

The three leaders, flanked by Jill Biden, Michelle Obama and Hillary Clinton, shared a moment of silence with the crowd at 8:46 a.m. to mark the time that the first plane hit. Heads bowed, they listened as relatives read the names of those who died.

The Bidens then flew to Shanksville, Pennsylvania, before heading back to the Washington area to visit the Pentagon memorial.

Nearly 3,000 people died in the attacks in New York, at the Pentagon and in Pennsylvania, where passengers on United Flight 93 overcame the hijackers and the plane crashed in a field, preventing another target from being hit.

Biden did not deliver remarks at any of the sites. He released a video on Friday to express his condolences to the loved ones of the victims and highlight the national unity that resulted, at least initially, after 9/11.

"The core of who we are is not divided," Biden said Saturday during a visit to a fire station after the Shanksville ceremony.

Rudy Giuliani, the mayor of New York at the time of the attacks, attended the ceremony. Former President Donald Trump, a New York native, did not.

In Shanksville, the Bidens participated in a wreath-laying ceremony at the Flight 93 National Memorial where names of the dead are etched on a white marble wall.

The passengers and crew who stormed the cockpit had stepped up in a crisis, Biden told reporters later. "That's genuine heroism," he said. He praised a speech given in Shanksville earlier in the day by former President George W. Bush, the Republican who had been in office less than a year when the hijacked planes changed the country, and the world.

The Bidens, Vice President Kamala Harris and second gentleman Doug Emhoff touched a memorial wreath at the site where a series of benches have been erected representing each of the 184 victims. They put their hands on their hearts, with Biden raising his in a salute, while "Taps" played.