NEW YORK --
The names of the Sept. 11 dead, some called out by children barely old enough to remember their fallen mothers and fathers, echoed across ground zero Sunday in a haunting but hopeful tribute on the 10th anniversary of the terror attack. "Hope can grow from tragedy," Vice President Joe Biden said at the Pentagon.
Weeping relatives of the victims streamed into a newly opened memorial. They placed pictures and flowers beside names etched in bronze, and traced them with pencil and paper. President Barack Obama and his predecessor, George W. Bush, bowed their heads and touched the inscriptions.
Obama, standing behind bulletproof glass and before the white oak trees of the memorial, read the Bible passage after a moment of silence at 8:46 a.m., when the first jetliner slammed into the north tower 10 years ago.
The president, quoting Psalm 46, invoked the presence of God as an inspiration to endure: "Therefore, we will not fear, even though the earth be removed, and though the mountains be carried into the midst of the sea."
The New York ceremony was the centerpiece of a day of remembrance across the country. It was a chance to reflect on a decade that changed American life, including two wars and the overhaul of everyday security at airports and in big cities.
In a tribute at the Pentagon, Vice President Joe Biden invoked a "9/11 generation of warriors."
"Never before in our history has America asked so much over such a sustained period of an all-volunteer force," he said. "So I can say without fear of contradiction or being accused of exaggeration, the 9/11 generation ranks among the greatest our nation has ever produced, and it was born - it was born - it was born right here on 9/11."
Defense Secretary Leon Panetta observed a moment of silence at 9:37 a.m., marking the time a jet struck the center of the nation's military. He paid tribute to 6,200 members of the U.S. military who have died in the Iraq and Afghan wars.
In Shanksville, Pa., a choir sang at the Flight 93 National Memorial, and a crowd of 5,000 listened to a reading of the names of 40 passengers and crew killed aboard the plane a decade ago.
The day's events took place under higher security than usual. In New York and Washington especially, authorities were on alert. Ahead of the anniversary, the federal government had warned those cities of a tip about a possible car-bomb plot. Police searched trucks in New York, and streets near the trade center were blocked. To walk within blocks of the site, people had to go through checkpoints.
In New York, family members began reading the names of 2,983 victims - 2,977 killed in New York, Washington and Pennsylvania on Sept. 11, 2001, and six killed in the first terror attack on the trade center, a truck bomb in 1993.
"You will always be my hero," Patricia Smith, 12, said of her mother.
Nicholas Gorki remembered his father, "who I never met because I was in my mother's belly. I love you, Father. You gave me the gift of life, and I wish you could be here to enjoy it with me."
Peter Negron, 21, whose father worked on the 88th floor of the north tower, said that in the decade since the attack, he had tried to teach his younger brother lessons he had learned from their father.
"I decided to become a forensic scientist," Negron said. "I hope that I can make my father proud of the young men my brother and I have become. I miss you so much, Dad."
Bush quoted a letter from President Abraham Lincoln to a mother who was believed to have lost five sons in battle during in the Civil War.
"I pray that our heavenly father may assuage the anguish of your bereavement," Bush said.
Obama and Bush were joined by their wives as they walked up to one of the two reflecting pools built over the towers' footprints, part of a Sept. 11 memorial that was opened for relatives of the victims.
Some family members held children on their backs who were not yet born when the towers were attacked.