Americans are marking 24 years since the Sept. 11, 2001, attacks with solemn ceremonies, volunteer work and other tributes honoring the victims.

Thousands of family members of the nearly 3,000 victims will gather with dignitaries and politicians at commemorations on Thursday in New York, at the Pentagon, and in Shanksville, Pennsylvania.

Others choose to mark the day at more intimate gatherings.

James Lynch, who lost his father, Robert Lynch, in the World Trade Center attack, mentioned that he and his family plan to take part in a ceremony near their hometown in New Jersey before spending time at the beach.

RELATED: September 11 coverage from WABC-TV Eyewitness News in New York over the years

“Grief is something that never really goes away,” remarked Lynch, as he, his partner, and his mother joined thousands of volunteers preparing meals for those in need at a 9/11 charity event in Manhattan the day before the anniversary. “Finding joy in the midst of that grief has played a significant role in my personal growth,” he added.

The memorial events coincide with a period of heightened political tension. Typically marked as a day of national unity, the 9/11 anniversary follows the recent killing of conservative activist Charlie Kirk, who was shot while speaking at a college in Utah.

The reading of names and moments of silence

Officials have stated that Kirk’s death is likely to lead to increased security at the 9/11 ceremony at the World Trade Center site in New York.

At ground zero in lower Manhattan, the names of the attack victims will be read aloud by their families and loved ones in a ceremony attended by Vice President JD Vance and his wife, second lady Usha Vance. Moments of silence will observe the exact times when hijacked planes hit the World Trade Center’s twin towers and when the buildings collapsed.

At the Pentagon in Virginia, the 184 service members and civilians killed when hijackers steered a jetliner into the headquarters of the U.S. military will be honored. President Donald Trump and first lady Melania Trump will attend the service before heading to the Bronx for a baseball game between the New York Yankees and Detroit Tigers Thursday evening.

And in a rural field near Shanksville, Pennsylvania, a similar ceremony marked by moments of silence, the reading of names and the laying of wreaths, will honor the victims of Flight 93, the hijacked plane that crashed after crew members and passengers tried to storm the cockpit. That service will be attended by Veterans Affairs Secretary Doug Collins.

Like Lynch, people across the country are also marking the 9/11 anniversary with service projects and charity works as part of a national day of service. Volunteers will be taking part in food and clothing drives, park and neighborhood cleanups, blood banks and other community events.

Reverberations from attacks persist

In all, the attacks by al-Qaida militants killed 2,977 people, including many financial workers at the World Trade Center and firefighters and police officers who had rushed to the burning buildings trying to save lives.

The attacks reverberated globally and altered the course of U.S. policy, both domestically and overseas. It led to the ” Global War on Terrorism ” and the U.S.-led invasions of Afghanistan and Iraq and related conflicts that killed hundreds of thousands of troops and civilians.

While the hijackers died in the attacks, the U.S. government has struggled to conclude its long-running legal case against the man accused of masterminding the plot, Khalid Sheikh Mohammed. The former al-Qaida leader was arrested in Pakistan in 2003 and later taken to a U.S. military base at Guantánamo Bay, Cuba, but has never received a trial.

The anniversary ceremony in New York was taking place at the National Sept. 11 memorial and Museum, where two memorial pools ringed by waterfalls and parapets inscribed with the names of the dead mark the spots where the twin towers once stood.

The Trump administration has been contemplating ways that the federal government might take control of the memorial plaza and its underground museum, which are now run by a public charity currently chaired by former New York City Mayor Michael Bloomberg, a frequent Trump critic. Trump has spoken of possibly making the site a national monument.

In the years since the attacks, the U.S. government has spent billions of dollars providing health care and compensation to tens of thousands of people who were exposed to the toxic dust that billowed over parts of Manhattan when the twin towers collapsed. More than 140,000 people are still enrolled in monitoring programs intended to identify those with health conditions that could potentially be linked to hazardous materials in the soot.