U.S. President Barack Obama said that America will never give in to fear and never succumb to mistrust and suspicion on the 10th anniversary of the worst-ever terror attack on North American soil.
"These past 10 years tell a story of resilience," Obama said during a speech in Washington, which followed a packed day that saw him visit all three of the Sept. 11 attack sites.
Obama said that the legacy of the tragedy is the soldiers who have fought in the decade since, along with the workers who have rebuilt the smashed towers and the people who have lived in freedom, despite fear.
"They will remember that we have overcome slavery and civil war, bread lines and fascism, recession and riots, Communism and, yes, terrorism," Obama said.
"It will be said of us that we kept that faith; that we took a painful blow, and emerged stronger."
Earlier, he joined his predecessor George W. Bush at the newly opened Memorial Plaza in New York to honour the memory of the dead.
Obama and Bush, accompanied by first lady Michelle Obama and former first lady Laura Bush, delivered brief readings Sunday morning from a podium where relatives of the victims later read out the names of the 2,977 people who died in the 9-11 attacks 10 years ago.
Obama read Psalm 46 that reminds the faithful that God is a refuge and strength that dwells in "his city." Bush read a civil war letter from former president Abraham Lincoln to a mother who lost all five of her sons.
Prime Minister Stephen Harper, who was in the official party, addressed the attacks which killed 24 Canadians. He described the events as "senseless and cowardly" and added: "While we honour and remember those who fell, this day will serve as a constant reminder that we are not immune from terrorism."
"We will continue to stand firm with our allies to help ensure such a tragedy never happens again," he said.
"Terrorism will not undermine our way of life."
Former New York Mayor Rudy Giuliani, who guided the city through much of its recovery after 9-11, was also present to say a small prayer.
"God bless every soul that we've lost. God bless the family members who have had to endure that loss and God bless our reunion in heaven," he said.
During the ceremony, an American flag fluttered over six stories of the signature skyscraper, One World Trade Center, which is rising quickly and will be the tallest in the U.S. when completed.
The sky was clear blue with scattered white clouds and a light breeze, not unlike the Tuesday morning 10 years ago when terrorists destroyed the twin towers of the World Trade Center.
Elijah Portillo, 17, whose father was killed in the attack, said he had never wanted to attend the anniversary because he thought he would feel angry. But this time was different, he said.
"Time to be a big boy," Elijah said. "Time to not let things hold you back. Time to just step out into the world and see how things are."
Nicholas Gorki remembered his father, "who I never met because I was in my mom's belly. I love you, Dad."
The ceremony also served as the memorial's official opening. It will open to the public Monday.
The memorial sits next to a construction project where office towers, a transportation hub and a cultural centre are taking shape. Along with the names of victims in bronze, there were two manmade waterfalls where the towers once stood. Dozens of white oak trees surrounded by skyscrapers compete for sunlight.
The anniversary revived memories of a September morning when terrorists crashed hijacked planes into the World Trade Center and the Pentagon, and a fourth plane crashed into a field in rural western Pennsylvania. It was a time to recall heroism and Samaritans and the unthinkable fear of nearly 3,000 killed at the hands of a global terror network led by Osama bin Laden, himself now dead.
America, global community mourns 9-11 victims
People across America gathered to pray at cathedrals in their major cities and to lay roses before fire stations in their smallest towns. Around the world, many others will do something similar since 9-11 affected them on that day, too.
But much of the weight of this year's ceremonies lies in what will largely go unspoken. There's the anniversary's role in prompting Americans to consider how the attacks affected them and the world as a whole. There is also the continuing struggle to understand 9-11's place in the lore of the nation.
"A lot's going on in the background," said Ken Foote, author of "Shadowed Ground: America's Landscapes of Violence and Tragedy," examining the role that veneration of sites of death and disaster plays in modern life. "These anniversaries are particularly critical in figuring out what story to tell, in figuring out what this all means. It forces people to figure out what happened to us."
On Saturday in rural western Pennsylvania, more than 4,000 people began to tell the story again.
At the dedication of the Flight 93 National Memorial near the town of Shanksville, Bush and former president Bill Clinton and Vice-President Joe Biden joined the families of the 40 passengers and crew aboard the jet who fought back against their hijackers.
"The moment America's democracy was under attack our citizens defied their captors by holding a vote," Bush said. Their choice cost them their lives.
The passengers and crew gave "the entire country an incalculable gift: They saved the Capitol from attack," an untold amount of lives and denied al-Qaida the symbolic victory of "smashing the centre of American government," Clinton said.
They were "ordinary people given no time at all to decide and they did the right thing," he said.
The Obamas visited the Wall of Names in Shanksville, where the president laid a wreath on the memorial featuring 40 marble slabs inscribed with the name of each victim of United Flight 93.
Worldwide events mark 10th anniversary
As the anniversary arrived around the world, citizens paid tribute in formal ceremonies and quiet moments.
In Japan, they gathered Sunday to lay flowers before a glass case containing a small section of centre steel from the World Trade Centre, and remembered 23 employees of Fuji Bank who never made it out of the towers.
A village in the Philippines offered roses, balloons and prayers for an American victim whose widower built 50 brightly colored homes there, fulfilling his late wife's wish to help the Filipino poor.
In Malaysia, Pathmawathy Navaratnam woke up and, as she has done every morning for 10 years, wished "good morning" to her son, a 23-year-old financial analyst who was killed in New York.
"He is my sunshine. He has lived life to the fullest, but I can't accept that he is not here anymore," said Navaratnam. "I am still living, but I am dead inside."
With files from The Associated Press
