Twenty-one years after the 9/11 terror attacks killed almost 3,000 Americans, the wounds wrought by that carnage are still fresh to Bonita Mentis.
Her sister, Shevonne Mentis, 25, was working for a financial firm in the World Trade Center when two of four planes commandeered that morning hit the twin towers. Bonita Mentis, at a commemoration Sunday in New York reading from the list of victims' names, said she still has the shoes her sister was looking for before leaving for work the morning she died.
"The day I was born I became your sister. The day you died you became my guardian angel," Mentis said. "We love you, we miss you and we will never forget you."
The ceremony at the National September 11 Memorial & Museum was one of many across the nation in remembrance of the attacks that rocked the world. President Biden laid a wreath at the Pentagon and first lady Jill Biden spoke in Shanksville, Pennsylvania. Events at all three sites where the strikes occurred included a reading of the names of those who died.
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Other communities around the country were holding candlelight vigils, interfaith services and other commemorations. Some Americans are joining in volunteer projects on a day that is federally recognized as Patriot Day and a National Day of Service and Remembrance.
President Joe Biden, speaking to a somber crowd in the rain outside the Pentagon, pledged to continue combatting terrorism and called on Americans to stand up for democracy.
"America itself changed that day," Biden said. "But what we will not change, and never will, is the character of this nation that the terrorist thought they could wound."
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In Shanksville, the names of the passengers and crew members were read with the ringing of the Bells of Remembrance starting at 10:03 a.m., the moment Flight 93 crashed. The plane went down after passengers and crew members tried to storm the cockpit.
"As we stand on this sacred and scarred earth, a record of our collective grief and a monument to the memories that live on each day, this is the legacy we much carry forward: Hope that defies hate," Jill Biden said.
Vice President Kamala Harris and husband Doug Emhoff attended the events in New York, but by tradition, no political figures speak at the ground zero ceremony. Family members of the victims once again reading the names of the fallen.
Six moments of silence were observed during the ceremony to mark when each of the World Trade Center towers were struck, when they fell, when a plane slammed into the Pentagon and when United Airlines Flight 93 crashed in Pennsylvania.
Firefighter Jimmy Riches’ namesake nephew wasn’t born when his uncle died in the towers, but younger Riches took the podium to pay tribute.
“You’re always in my heart. And I know you are watching over me,” he said.
The attacks were the work of 19 al-Qaeda conspirators who hijacked two passenger jets departing from Boston, one from Newark, N.J., and one from outside Washington. They turned the planes into weapons, with two slamming into and toppling the twin towers in New York, one hitting the Pentagon and one, likely headed for the U.S. Capitol, crashing into the Shanksville field.
The deadly morning spurred a global “war on terror" highlighted by two decades of combat in Afghanistan and the 2011 killing of Osama bin Laden, founder of the Islamist militant group. A month ago a U.S. drone strike killed Ayman al-Zawahri, another key al-Qaeda figure who helped plot the 9/11 attacks. And the self-proclaimed mastermind of the attacks, Khalid Shaikh Mohammed, is in custody awaiting a long-postponed military tribunal.
"America's determination to keep our country safe will never waiver," Defense Secretary Lloyd Austin said at the Pentagon commemoration. "We will always remember, we will always stand guard over this democracy. And we will always seek to be worthy of those who we lost."
Contributing: The Associated Press