NEW YORK (WCBS 880) – New York City and the nation marked the 20th anniversary of the 9/11 terrorist attacks on Saturday.
Hundreds of family members gathered at the 9/11 Memorial, where they read the names of their loved ones and observed six moments of silence. Among the officials in attendance was President Joe Biden, who traveled to all three attack sites before returning to his home in Wilmington, Delaware.
Listen to special coverage of the 20th anniversary of 9/11:

On a sunny Tuesday 20 years ago, terrorists hijacked four planes. Two planes were flown into the World Trade Center and one into the Pentagon. The fourth crashed into a field near Shanksville, Pennsylvania, as passengers fought back against the hijackers.
The attacks killed 2,977 people that day and injured thousands. Many more were sickened or killed by 9/11-related illnesses in the years that followed.



Here are the latest updates as the nation remembers that day:
5:40 p.m. -- President Joe Biden arrives home via motorcade after landing on a parking lot at Brandywine Creek State Park at 5:24 p.m.
4:34 p.m. -- President Joe Biden and First Lady Jill depart Virginia for their home in Wilmington, Delaware, on the Marine One helicopter.
4:00 p.m. –– President Joe Biden and first lady, Jill, joined Vice President Kamala Harris and her husband, Douglas Emhoff, to participate in a wreath-laying ceremony at the Pentagon in Arlington, Virginia.
“These memorials are really important, but they're also incredibly difficult for the people who were affected by them because it brings back that moment you got the phone call. It brings back that instant you got the news, no matter how many years go by," Biden told reporters at the event.

Biden praised Bush’s speech earlier in the day before speaking to national unity. He mentioned that he took photos with boys wearing Trump hats at the firehouse.
“Are we going to, in the next four, five, six, ten years, demonstrate that democracies can work, or not?" Biden asked.
2:30 p.m. -- President Joe Biden meets with Shanksville Volunteer Fire Department during an unannounced visit. He spent more than an hour speaking with first responders and their families, posing for photos.
Speaking at the memorial service, Mayor Bill de Blasio says, "9/11 is personal for every New Yorker. Every one of us can tell you not only where we were when we heard, but who we lost in our lives – but for you, it's a magnitude so much greater. For the men and women of this department, many of you lost members of your own blood family, but you lost so many members of your FDNY family, and it surrounds you and it's painful every day. And yet, you have persevered in a way that has the admiration of not only the entire nation, but the entire world. It is impossible to put into words the respect that you have won for fighting through the unbelievable, the unimaginable, and always being there to protect the people of this city."

1:45 p.m. -- The Port Authority of New York and New Jersey holds its Interfaith Remembrance Service at North Oculus Plaza to honor the 84 Port Authority employees killed on 9/11.


1:30 p.m. -- Former President Donald Trump makes a surprise visit to FDNY and NYPD members in Midtown Manhattan. Video shows the 45th president— who was not at the 9/11 Memorial commemoration ceremony earlier in the day—speaking with firefighters and police officers at FDNY Engine 8/Ladder 2/Battalion 8 and the NYPD’s 17th Precinct stationhouse.
12:50 p.m. -- The reading of victims' names concludes at the 9/11 Memorial in lower Manhattan.
12:25 p.m. -- President Joe Biden lays a wreath at the Flight 93 Memorial under a clear, blue sky. The memorial is home to the Wall of Names, where the names of the passengers and the crew from the flight are inscribed in marble.
The president and First Lady Jill Biden then walk with relatives of the crash victims into the grassy field where the jet crashed.

12:15 p.m. -- President Joe Biden and First Lady Jill Biden arrive at the Flight 93 Memorial, where they're greeted by Interior Secretary Deb Haaland.
11:15 a.m. -- Vice President Kamala Harris speaks at the Flight 93 Memorial: "We stand today with all those who lost someone on September 11, 2001 and the aftermath of the attacks."
“So many in our nation -- too many in our nation -- have deeply felt the passage of time these past 20 years," the vice president says. "Please know your nation sees you and we stand with you and we support you.”

11 a.m. -- Former President George W. Bush speaks at the Flight 93 Memorial in Shanksville, Pennsylvania, where Flight 93 crashed after passengers and crew fought back against the terrorists: "We learned that bravery is more common than we imagined, emerging with sudden splendor in the face of death."
Bush, who was president during the attacks, commends the courage of the Flight 93 passengers and crew: “The 33 passengers and seven crew of Flight 93 could have been any group of citizens selected by fate. In a sense, they stood in for us all... The terrorists soon discovered that a random group of Americans is an exceptional group of people.”
The 43rd president encourages Americans to put aside their political differences in the spirit of what he saw after 9/11: "So much of our politics has become a naked appeal to anger, fear and resentment... On America's day of trial and grief, I saw millions of people instinctively grab their neighbor's hand and rally to the cause of one another."

10:50 a.m. – Members of the FDNY’s Battalion 57 lead a procession over the Brooklyn Bridge to the Co-Cathedral of St. Joseph in Brooklyn. Firefighters from across the country, as well as personnel from FDNY firehouses throughout the city, are taking part.
10:30 a.m. -- "Hamilton" actor Chris Jackson performs "Never Alone" at the memorial.




10:28 a.m. -- A sixth and final moment of silence is observed to mark the time the North Tower fell.
10:03 a.m. -- A moment of silence is observed to mark the time United Airlines Flight 93 crashed near Shanksville, Pennsylvania.
10 a.m. -- At a Pentagon ceremony, Defense Secretary Lloyd Austin says that “we remember not just who our fallen teammates were, but the mission that they shared.”
9:59 a.m. -- A moment of silence is observed to mark the time the South Tower fell.
9:40 a.m. -- Broadway actor and singer Kelli O'Hara performs “You’ll Never Walk Alone” at the memorial.



9:37 a.m. -- A moment of silence is observed to mark the time American Airlines Flight 77 struck the Pentagon.
9:05 a.m. -- Bruce Springsteen performs an acoustic rendition of "I'll See You In My Dreams" at the memorial.



9:03 a.m. -- A moment of silence is observed to mark the time United Airlines Flight 175 struck the South Tower.
8:55 a.m. -- Families continue to read names of loved ones killed in the attacks.


8:47 a.m. -- Relatives have begun reading the names of the 2,983 people who were killed in the attacks of September 11, 2001, and February 26, 1993.
8:46 a.m. – The NYPD holds ceremonies at every command center across the five boroughs. The names of the 23 members of the NYPD who were killed in the line of duty on 9/11 are read.
8:46 a.m. -- A moment of silence is observed to mark the time American Airlines Flight 11 struck the North Tower. Attendees bow their heads. A bell chimes, signaling the start of the commemorations marking 20 years since the attacks.

8:43 a.m. -- An honor guard carrying a single American flag arrives at the memorial with drums and bagpipes. Family members hold photos of their loved ones high over their heads. The National Anthem begins.
8:30 a.m. -- Many officials have arrived, including presidents Joe Biden, Barack Obama and Bill Clinton. Mayors Bill de Blasio, Michael Bloomberg and Rudy Giuliani, as well as senators Chuck Schumer and Kirsten Gillibrand, and other members of Congress, are also in attendance, along with hundreds of family members.


7:30 a.m. -- Gov. Kathy Hochul tweets: "Twenty years ago today, nearly three thousand people lost their lives in the horrific and unprecedented acts of terror against our state and our nation. We will #NeverForget"
7:15 a.m. -- Former President Barack Obama lauded the heroes of 9/11 — and of the years since — in a message to mark the 20th anniversary of the terror attacks: “One thing that became clear on 9/11 — and has been clear ever since — is that America has always been home to heroes who run towards danger in order to do what is right.”
7 a.m. -- Family members are arriving at the 9/11 Memorial for the commemoration ceremony.



The Associated Press contributed to this report.