PHOTOS: Remembering the Sept. 11 terror attacks, 18 years later

Americans are remembering the terror attacks of Sept. 11, 2001, which claimed 3,000 lives when hijacked planes slammed into the World Trade Center, the Pentagon and a field near Shanksville, Pennsylvania.

Eighteen years after the deadliest terrorist attack on American soil, the nation is still grappling with the aftermath at Ground Zero, in Congress and beyond.

All the victims’ names are read aloud at the Ground Zero ceremony in New York, where moments of silence and tolling bells mark the moments when the aircraft crashed and the Trade Center’s twin towers fell.

WATCH: Anniversary ceremonies in NY mark 18 years since 9/11 terrorist attacks

There has also been growing awareness in recent years of the suffering of another group of people tied to the tragedy: firefighters, police and others who died or fell ill after exposure to the wreckage and the toxins unleashed in it.

While research continues into whether those illnesses are tied to 9/11 toxins, a victims compensation fund for people with potentially Sept. 11-related health problems has awarded more than $5.5 billion so far. Over 51,000 people have applied.

The Associated Press contributed to this report.

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New York Fire Department members attend a second funeral service for FDNY firefighter Michael Haub in Franklin Square, N.Y., Tuesday, Sept. 10, 2019. The firefighter from Long Island who died in the World Trade Center attacks is being remembered for a second time on the eve of the 18th anniversary of 9/11. Friends and family gathered at the memorial service for Haub on Tuesday in Franklin Square. Last week, the New York City medical examiner identified more of his remains recovered at ground zero.

New York Fire Department members attend a second funeral service for FDNY firefighter Michael Haub in Franklin Square, N.Y., Tuesday, Sept. 10, 2019. The firefighter from New York’s Long Island who died in the World Trade Center attacks is being remembered for a second time on the eve of the 18th anniversary of 9/11. Friends and family gathered at the memorial service for Haub on Tuesday in Franklin Square. Last week, the New York City medical examiner identified more of his remains recovered at ground zero.

A visitor to the Flight 93 National Memorial in Shanksville, Pa., views the Wall of Names on Tuesday, Sept. 10, 2019, as the nation prepares to mark the 18th anniversary of the Sept. 11, 2001 attacks.

Visitors to the Flight 93 National Memorial in Shanksville, Pa., participate in a sunset memorial service on Tuesday, Sept. 10, 2019, as the nation prepares to mark the 18th anniversary of the Sept. 11, 2001 attacks.

The Tribute in Light rises above the lower Manhattan skyline, Tuesday, Sept. 10, 2019 in New York. Wednesday marks the 18th anniversary of the terror attacks against the United States of Sept. 11, 2001.

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An American flag is unfurled at sunrise at the Pentagon in Washington on the 18th anniversary of the September 11th attacks, Wednesday, Sept. 11, 2019. (AP/Patrick Semansky)

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A U.S. Flag hanging from a steal girder, damaged in the Sept. 11, 2001 attacks on the World Trade Center, blows in the breeze at a memorial in Jersey City, N.J., Sept. 11, 2019 as the sun rises behind One World Trade Center building and the re-developed area where the Twin Towers of World Trade Center once stood in New York City on the 18th anniversary of the attacks. (AP/J. David Ake)

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New York City firefighters take a position in front of a memorial on the side of a firehouse adjacent to One World Trade Center and the 9/11 Memorial site during ceremonies commemorating the 18th anniversary of the 9/11 terrorist attacks in New York on Wednesday, Sept. 11, 2019. (AP/Craig Ruttle)

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New York City firefighters stand at attention in front of a memorial on the side of a firehouse adjacent to One World Trade Center and the 9/11 Memorial site during ceremonies commemorating the 18th anniversary of the 9/11 terrorist attacks in New York on Wednesday, Sept. 11, 2019. (AP/Craig Ruttle)

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People gather for a ceremony marking the 18th anniversary of the attacks of Sept. 11, 2001 at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. (AP/Mark Lennihan)

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People gather for a ceremony marking the 18th anniversary of the attacks of Sept. 11, 2001 at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. (AP/Mark Lennihan)

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A couple sits quietly prior to the start of a ceremony marking the 18th anniversary of the attacks of Sept. 11, 2001 at the National September 11 Memorial, Wednesday, Sept. 11, 2019, in New York. (AP/Mark Lennihan)

President Donald Trump and first lady Melania Trump participate in a moment of silence honoring the victims of the Sept. 11 terrorist attacks, on the South Lawn of the White House, Wednesday, Sept. 11, 2019, in Washington.

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A flag hangs on the Pentagon before a ceremony in observance of the 18th anniversary of the September 11th attacks at the Pentagon in Washington, Wednesday, Sept. 11, 2019. (AP/Patrick Semansky)

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Flowers rest on a bench bearing a name in memory of retired U.S. Army Lieutenant Colonel Gary Smith before a ceremony in observance of the 18th anniversary of the September 11th attacks at the Pentagon in Washington, Wednesday, Sept. 11, 2019. (AP/Patrick Semansky)

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A flag hangs on the Pentagon before a ceremony in observance of the 18th anniversary of the September 11th attacks at the Pentagon in Washington, Wednesday, Sept. 11, 2019. (AP/Patrick Semansky)

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A woman stands next to the north pool prior to a ceremony marking the 18th anniversary of the attacks of Sept. 11, 2001 at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. (AP/Mark Lennihan)

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Louis Gonzalez makes a rubbing of his sister’s name at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. Aida Rosario was killed during the attacks of Sept. 11, 2001. (AP/Mark Lennihan)

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A woman wipes away tears as she stands next to the north pool prior to a ceremony marking the 18th anniversary of the attacks of Sept. 11, 2001 at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. (AP/Mark Lennihan)

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Flowers and an American flag rest on a bench bearing a name in memory of Khang Ngoc Nguyen before a ceremony in observance of the 18th anniversary of the September 11th attacks at the Pentagon in Washington, Wednesday, Sept. 11, 2019. (AP/Patrick Semansky)

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The names are read of victims of the Sept. 11 attacks during a ceremony marking the 18th anniversary at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. (AP/Mark Lennihan)

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Family members hold up photos during a ceremony marking the 18th anniversary of the attacks of Sept. 11, 2001 at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. (AP/Mark Lennihan)

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Members of Congress gather at the Capitol to observe the anniversary of the Sept. 11, 2001, terror attacks on America, in Washington, Wednesday, Sept. 11, 2019. On front row, from left are Minority Whip Steve Scalise, R-La., House Republican Leader Kevin McCarthy, D-Calif., House Speaker Nancy Pelosi, D-Calif., and House Majority Leader Steny Hoyer, D-Md. (AP/J. Scott Applewhite)

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President Donald Trump and first lady Melania Trump place a wreath and will participate in a moment of silence honoring the victims of the Sept. 11 terrorist attacks, Wednesday, Sept. 11, 2019, at the Pentagon. (AP/Evan Vucci)

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A man holds a photo of a victim during a ceremony marking the 18th anniversary of the attacks of Sept. 11, 2001 at the National September 11 Memorial, Wednesday, Sept. 11, 2019 in New York. (AP/Mark Lennihan)

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The morning sun strikes the East Front of the Capitol as the flag flies at half staff to mark the anniversary of the Sept. 11, 2001, terror attacks on America, in Washington, Wednesday, Sept. 11, 2019. (AP/J. Scott Applewhite)

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People walk past an American flag at the start of a work day, at the Oculus, part of the World Trade Center transportation hub in New York, Wednesday, Sept. 11, 2019, on the 18th anniversary of 9/11 terrorist attacks. (AP/Wong Maye-E)

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Chris LeClair, second from left, of Woodbridge, Va., visits the grounds of the National 9/11 Pentagon Memorial with his children Emily, age 12, from left, Melody, age 11, and Ash, age 3, before a ceremony in observance of the 18th anniversary of the September 11th attacks at the Pentagon in Washington, Wednesday, Sept. 11, 2019. LeClair’s late father-in-law, U.S. Navy information systems technician Gregg H. Smallwood, was killed inside the Pentagon when American Airlines Flight 77 struck the building. (AP/Patrick Semansky)

Will Vitka

William Vitka is a Digital Writer/Editor for WTOP.com. He's been in the news industry for over a decade. Before joining WTOP, he worked for CBS News, Stuff Magazine, The New York Post and wrote a variety of books—about a dozen of them, with more to come.