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."
In a reminder of the war that started in the wake of the attacks, 77 American soldiers were wounded when a Taliban suicide bomber detonated a truck bomb outside the gates of a U.S. base in eastern Afghanistan. Two Afghans were also killed.
On Sunday, the focus turned to ceremonies at the Pentagon, just outside Washington, D.C., and in lower Manhattan. Obama planned to attend events at the sites and was to speak at a Sunday evening service at the Kennedy Center.
Among the names being read in New York were those of 37 of Lt. Patrick Lim's fellow officers from the police department of the Port Authority of New York and New Jersey.
Lim, assigned to patrol the trade center with an explosives detection dog, rushed in to the north tower after it was hit to help evacuate workers. He and a few others survived despite still being inside a fifth-floor stairwell when the building fell.
In the years since, Lim said he has wrestled with survivor's guilt. He took shelter in selective memory, visualizing the ground covered with women's shoes amid the destruction. "That's how I got through that because what was attached to the shoes was a lot worse," Lim said.
The 10th anniversary has forced Lim to revisit an experience he's worried too many people have pushed from their minds. But the approach of Sunday's ceremonies has convinced him of the value of revisiting Sept. 11, both for himself and others.
When it happened, talking about the events of that day "wasn't easy for me. This was very difficult. But it became ... a catharsis," he said. "What I want is for people to remember what happened."
The hundreds of ceremonies across the country and around the globe included memorial Mass at St. Patrick's Cathedral in New York and a ceremony featuring nine-stories-tall replicas of the twin towers on a plaza in Paris.
Others observed the day as a time to serve. Thousands cleaned public parks, renovated community centers and gave blood as they did in the days after the 2001 attacks. Some said they were trying to reclaim goodwill that they said has been lost amid political rancor and economic fear.
"As unfortunate as it was, it seemed like it put us all back into the frame of mind that life wasn't just about me," said Yvette Windham, 44, who joined 200 people to build seven new homes in a Nashville, Tenn., neighborhood.
The White House posted a photo on Twitter of Obama and one of his daughters, Malia, preparing food at a community kitchen in Washington. "How are you serving" on Sept. 11, the post asked.
David Paine, president and co-founder of My Good Deed, estimated four in 10 Americans planned to observe the anniversary by volunteering or doing some form of charity. Family members started the organization in 2002 to make Sept. 11 a national day of service.
Associated Press writers Tamara Lush in Nashville, Tenn., and Joe Mandak in Shanksville, Pa., contributed to this report.