New York City Mayor Zohran Mamdani shook hands with former Mayor Rudy Giuliani as families, mourners and politicians gathered at the site of the September 11 attacks in New York City, 25 years after the devastation.

Mamdani, who was 9 years old and in his fourth grade classroom on the Upper West Side when the World Trade Center was hit, has faced an avalanche of anti-Muslim rhetoric and pleas from right-wing critics, including Giuliani, to avoid this week’s 9/11 ceremonies.

The city’s first Muslim mayor has steered this week’s commemorative events to ensure focus remains on the families, victims, first responders and the city’s recovery, and his office released thousands of never-before-seen documents that appeared to reveal that Giuliani’s administration and subsequent mayors knew the dangers of the toxic aftermath despite assuring the public of lower Manhattan’s safety.

Giuliani, once seen as “America’s mayor” in the wake of the attacks, has spent the last several years in courtrooms across the country battling criminal indictments, bankruptcy and a defamation lawsuits surrounding the 2020 presidential election as he became consumed by baseless conspiracy theories.

The 82-year-old former mayor joined pleas from right-wing figures calling on Mamdani to avoid Friday’s memorial. Giuliani has said his presence “offends” him and claimed Mamdani is “disturbing the people who are the most important people at that celebration.”

“He stands in direct support of the movement that killed their children,” Giuliani said. “You’d have to be a fool to resist that.”

Twenty-five years ago, a commercial airliner hijacked by al-Qaeda terrorists struck the North Tower of the World Trade Center in lower Manhattan, the first of four attacks on September 11, 2001 that killed nearly 3,000 people and set in motion a series of profoundly world-changing events.

Mourning Americans are gathering across the country and at the site of the attacks for a familiar annual ritual: reading the names of the people who were killed at the World Trade Center, at the Pentagon, and in a field in Pennsylvania.

A ceremony at the site of the Twin Towers begins with a moment of silence at 8:46 a.m., the moment the first plane, American Airlines Flight 11, hit the 96th floor of the skyscraper. More moments of silence will follow to recognize the moment a second plane struck the building when the towers collapsed, when the Pentagon was hit, and when United Airlines Flight 93 crashed in Shanksville, Pennsylvania, after passengers fought back against the plane’s hijackers.

All living former presidents will attend the Manhattan ceremony, along with Vice President JD Vance.

President Donald Trump, however, will not attend, purportedly because he is not allowed to deliver remarks. The president will attend a ceremony at the Pentagon.

But for the first time, the ceremony at the National September 11 Memorial and Museum will hold a seventh moment of silence to honor people who died from illnesses related to the attacks.

This week, more than 170,000 pages of newly released records, never before shown to the public, revealed that New York City officials knew of potential dangers from exposure to Ground Zero toxins in the aftermath of the attacks despite repeated assurances to the public that the air was safe to breathe.

Over the two decades that followed, thousands of first responders and other New Yorkers developed lung disease, neurological illnesses and cancers linked to expansive recovery efforts and their lives in the shadow of the attack, as clouds of chemicals, cement dust, asbestos and other toxic debris lingered in the air and in buildings.

According to the World Trade Center Health Program, more than 9,000 people have died from 9/11-related illnesses, including 600 firefighters — exceeding the nearly 3,000 people killed in the attacks themselves and the more than 300 firefighters who died in the rescue efforts.

In Shanksville, mourners will read the names of the passengers and crew members of Flight 93, on which passengers fought back against four hijackers and forced the plane away from Washington, D.C., averting what was expected to be another devastating attack on the nation’s capital.