(NewsNation) — New York City marked the 23rd anniversary of the 9/11 attacks at ground zero on Wednesday morning.

Sept. 11 — the date when terrorists hijacked planes and killed nearly 3,000 people in 2001 — falls in the thick of the presidential election season every four years, and it comes at an especially pointed moment this time.

President Joe Biden, former President Donald Trump and Vice President Kamala Harris are honoring those who were lost in the attacks in New York City and Shanksville, Pennsylvania. 

9/11 ground zero observance

A moment of silence was held to honor the men and women who lost their lives 23 years ago when two planes — United Airlines Flight 175 and American Airlines Flight 11 — were hijacked by al-Qaida terrorists and crashed into the World Trade Center in New York City.

Trump and running mate Sen. JD Vance arrived at the site around 8 a.m. and posed for photographs with some in the audience. Harris arrived with Biden about a half-hour later, to cheers of “Kamala!” from some audience members.

Biden and Trump shook hands, and then the president and Harris stood only a few feet from Trump and Vance, with former New York Mayor Michael Bloomberg between them.

But the political backdrop wasn’t top-of-mind for victims’ relatives such as Cathy Naughton, who came to the ceremony to honor 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 people remember always, and say the names always and never forget.”

The attacks killed 2,977 people and left thousands of bereaved relatives and scarred survivors. The planes carved a gash in the Pentagon, the U.S. military headquarters, and brought down the World Trade Center’s twin towers, which were among the world’s tallest buildings.

The catastrophe also altered U.S. foreign policy, domestic security practices and the mindset of many Americans who had not previously felt vulnerable to attacks by foreign extremists.

9/11 Shanksville observance

Americans descended on Shanksville, Pennsylvania, to visit the Flight 93 National Memorial on Wednesday, to honor and remember those who died in this southwestern Pennsylvania expanse after hijackers attempted to take down the aircraft.

Harris and Biden, NewsNation partner The Hill reported, laid a white and red wreath down at the memorial site. Both leaders were silent and did not address the crowd as they walked through the memorial then went out to the crash site. Trump visited Shanksville as well, visiting a volunteer fire department. He then made a surprise stop to a firehouse in New York City.

Flight 93 made its final descent, chaos unfolding aboard as flight crew members and passengers fought to take back control of the plane.

The plane was intended to hit Washington, D.C., but the plan was thwarted when passengers and crew members stepped into action.

The plane crashed in a field near Shanksville, Pennsylvania, killing everyone on board.

9/11 Pentagon observance

Hijackers aboard American Airlines Flight 77 targeted the Pentagon, killing 64 people on the aircraft and 125 people in the building.

The Pentagon Memorial honors those lives that were lost on Sept. 11, 2001.

During an observance at the site, Defense Secretary Lloyd Austin said the damage to the Pentagon building was repaired, “but we know that we cannot repair the damage” to the hearts of those whose loved ones died.

“No words can take away your grief.No amount of time can make sense of the worst terrorist attack in American history,” Austin said. “And I know that for those whose lives were changed forever on 9/11, it can feel as if more and more Americans are returning to normal life on each new Sept. 11.But not here. Not at the Pentagon.Because we remember. The men and women of the Department of Defense remember. And we always will.”

During his remarks, Austin mentioned that some survivors and first responders continue to fight illnesses that stemmed from the attacks decades later.

Lawmakers mark 9/11 anniversary

Biden and Harris traveled from ground zero to the Flight 93 National Memorial in Shanksville on Wednesday to mourn the victims of the attacks at all three sites.

Trump is also planning to visit Shanksville for a Flight 93 memorial, according to a campaign official. 

Presidential candidates have overlapped on 9/11 anniversaries during election years before. In 2016, Trump and then-Democratic nominee Hillary Clinton visited ground zero on the 15th anniversary of the attack. They arrived separately and did not appear to interact.

Trump’s 9/11 controversy

The former president has a complicated history with the attacks. Trump has made dubious claims about his presence at ground zero in the days after the attacks, and has made unfounded accusations about Muslim Americans in New Jersey cheering as the World Trade Center came down. 

This year’s anniversary events come after Trump faced widespread backlash for bringing his campaign staff to an event at Arlington National Cemetery marking the anniversary of the Kabul, Afghanistan, bombing on Aug. 26, 2021, that killed 13 U.S. service members and dozens of Afghan civilians. 

Trump said that he was invited to the cemetery by the family of one of the dead service members, but the Army said his campaign violated laws against politicizing the military cemetery after reports that two of his campaign staffers pushed aside a cemetery official trying to enforce the rules. 

The former president has also angered many 9/11 families in recent years as his golf courses have played host to the LIV Golf tour, which is backed by Saudi Arabia’s Public Investment Fund. The 9/11 families are waging an ongoing legal battle seeking to hold Saudi Arabia responsible for its alleged role in the 2001 attacks. Trump has largely ignored the criticism.

The group, 9/11 Justice, released a statement Tuesday criticizing reports that PGA Tour officials, including Tiger Woods, are meeting Saudi representatives for talks on a potential merger with LIV Golf. 

The 9/11 Commission established by Congress said in 2004 that it uncovered “no evidence that the Saudi government as an institution or senior Saudi officials individually funded” al-Qaida, and that remains the official position of the United States. 

However, the FBI has reportedly continued investigating allegations of logistical support that a Saudi consular official and a suspected Saudi intelligence agent provided to hijackers.

Video: Saudi official allegedly ‘cases’ US Capitol

The allegations of Saudi involvement were back in the news this summer after a video was released showing Omar al-Bayoumi, a Saudi intelligence operative, giving a tour of landmarks in Washington, D.C., in 1999, around the same time al-Qaida was believed to be selecting targets for its attacks. 

Investigators for 9/11 Families United claim the video shows a Saudi intelligence official “casing” the U.S. Capitol around the same time al-Qaida was deciding on targets for the attacks.

The group sent NewsNation the video after a judge released it by court order. The video has been referenced in court filings as part of a civil lawsuit filed by victims’ families against Saudi Arabia seeking to hold the country liable for its role, if any, in the attacks.

Fifteen of the 19 hijackers were from Saudi Arabia and all were members of al-Qaida, then led by Osama bin Laden, who was born in Saudi Arabia and whose family had close ties to the Saudi royal family.

The video included shots of entrances, exits and security checkpoints at the U.S. Capitol, which federal officials believe was the target of Flight 93 before passengers forced their way into the cockpit and the plane crashed in Pennsylvania. 

Push to make 9/11 a federal holiday

9/11 families and their representatives in Congress are also pushing to make 9/11 a federal holiday. Rep. Mike Lawler, R-N.Y., introduced a bill last year that would close schools and other government buildings on Sept. 11 to honor those who died in the attacks. 

And with the World Trade Center Health Program anticipating a funding shortage in the coming years, a recurring issue, Sen. Kirsten Gillibrand, D-N.Y., this summer reintroduced a bill that would ensure the program’s funding for the rest of its existence. 

Neither Lawler’s nor Gillibrand’s bills have made it out of committee.

NewsNation’s Kellie Meyer, The Hill, Colin Meyn and The Associated Press contributed to this report.