NEW YORK (AP) — The United States remembered the lives lost and transformed by 9/11, marking an anniversary steeped in presidential campaign politics as President Joe Biden, former President Donald Trump and Vice President Kamala Harris stood together at Ground Zero on Wednesday.

September 11 — the date in 2001 when nearly 3,000 people were killed in hijacked plane attacks — falls every four years in the middle of the presidential election season, and this time at a special time. The anniversary ceremony at the World Trade Center brought Harris and Trump, the Democratic and Republican nominees, face-to-face just hours after their first-ever debate on Tuesday night.

Trump and running mate Sen. J.D. Vance arrived at the trade center around 8 a.m. and posed for photos with several people in the audience. Harris arrived about a half hour later with Biden, to cheers of “Kamala!” from several in the audience.

Biden and Trump shook hands, and former New York Mayor Michael Bloomberg appeared to facilitate a handshake between Harris and Trump. The presidential rivals then stood just feet apart, with Biden and Bloomberg between them, as the commemoration began with the ringing of a bell and a moment of silence.

Former President Donald Trump shakes hands with Vice President Kamala Harris during a ceremony marking the 23rd anniversary of the September 11, 2001, attacks on the World Trade Center at the 9/11 Memorial and Museum in Manhattan. Photo by Mike Segar/Reuters

The political backdrop was not the main concern for relatives of victims such as Cathy Naughton, who came to pay tribute to her cousin Michael Roberts, one of the hundreds of firefighters killed in the attack.

Twenty-three years later, “it’s just so raw,” she said. “We want to make sure that people always remember, and always say the names and never forget.”

“It doesn’t get easier every year,” she added.

Regardless of the campaign calendar, organizers of anniversary ceremonies have long taken pains to keep the focus on victims. For years, politicians were mere spectators at Ground Zero commemorations, with the microphone going instead to family members who read the names of victims aloud.

If politicians “care about what’s really going on, fine. Be here,” said Korryn Bishop, who lost her cousin John F. McDowell Jr. “If they’re just here for political influence, that bothers me.”

Biden, who arrived on Sept. 11 and likely has a half-century of political career behind him, was later scheduled to attend ceremonies with Harris in Pennsylvania and at the Pentagon, the three sites where commercial airliners crashed after al Qaeda operatives took over on Sept. 11, 2001. Trump was also scheduled to attend the Flight 93 National Memorial near rural Shanksville, Pennsylvania.

Biden and Harris are expected to lay a wreath at the site of the crash of Flight 93. Watch below.

Officials later concluded that the plane that crashed there was en route to Washington. It crashed after crew members and passengers tried to take control from the hijackers.

The attacks killed 2,977 people and left thousands of survivors and scars. The planes tore a hole through the Pentagon, the U.S. military headquarters, and brought down the trade center’s Twin Towers, among the world’s tallest buildings.

The disaster also changed U.S. foreign policy, domestic security practices, and the mindset of many Americans who previously did not feel vulnerable to attacks from foreign extremists.

The effects were felt around the world and across generations as the U.S. responded by leading a “Global War on Terrorism,” which included invasions of Afghanistan and Iraq. Those operations killed hundreds of thousands of Afghans and Iraqis and thousands of U.S. troops, and Afghanistan became the site of America’s longest war.

As the complex legacy of 9/11 continues to unfold, communities across the country have developed commemorative traditions that range from wreath-laying to flag displays, from marches to police radio announcements. Community service projects also mark the anniversary, which Congress has designated both Patriot Day and a National Day of Service and Remembrance.

Biden and Harris are expected to lay a wreath at the Pentagon at 5 p.m. EDT. Watch live below.

At Ground Zero, presidents and other officials read poems, portions of the Declaration of Independence, and other texts during the first commemorations.

But that ended after the National Sept. 11 Memorial and Museum decided in 2012 to limit the ceremony to relatives reading the names of the victims. Bloomberg was chairman at the time and remains so.

Politicians and candidates were still able to attend the event. Many did, especially New Yorkers who held office at the time of the attacks, such as former Secretary of State Hillary Clinton, who was a U.S. senator at the time.

She and Trump met at the 2016 9/11 memorial, which became a charged chapter in the narrative history of that year’s presidential campaign.

Clinton, then the Democratic nominee, abruptly left the ceremony, tripped while waiting for her motorcade and later revealed that she had been diagnosed with pneumonia a few days earlier. The episode drew renewed attention to her health, which Trump had been doubting for months.

In 2008, then-senators and presidential campaign rivals John McCain and Barack Obama made a visible effort to put politics aside on the anniversary, visiting Ground Zero together to pay their respects and lay flowers in a reflecting pool near what was then a well.

Of course, relatives of victims occasionally send their own political messages to the ceremony, with readers typically making brief comments after the names are read out.

Some family members have used the forum to lament divisions among Americans, urge leaders to prioritize national security, recognize the victims of the war on terror, complain that officials are politicizing 9/11 and even criticize individual officials.

But most readers stick to tributes and personal reflections. Increasingly, they come from children and young adults born after the attacks killed a parent, grandparent, aunt or uncle.

—Jennifer Peltz and Karen Matthews, Associated Press

Associated Press journalists Julie Walker and Adriana Gomez Licon contributed.