Hundreds of grieving family members gathered amid the white tombstones of Arlington National Cemetery yesterday to mark the third anniversary of the Sept. 11 attacks, as people across the nation observed the day with bagpipes and bugles, prayers and moments of silence.

From dawn until dusk, it was a day of mourning and solemn ceremony. New Yorkers converged on Ground Zero, where the names of the 2,749 people killed there were read aloud, often through tears and cracking voices. Bells rang out across the field in Shanksville, Pa., where United Airlines Flight 93 crashed, as 1,500 people paid their respects.

In Washington, President Bush and first lady Laura Bush observed a moment of silence on the south lawn of the White House at 8:46 a.m., when the first plane hit the World Trade Center. The victims of the Pentagon attack also were remembered at the Arlington County Courthouse, where a bell tolled 184 times, once for each one who died. Then, just before sunset, Fairfax High School's a cappella group sang "Amazing Grace" next to City Hall, and a lone bagpiper played as residents held candles.

With the tributes to the fallen came reminders that the war against terror continues, that it is still a time of color-coded warnings and constant threat. Volunteers in Alexandria urged passersby to remain vigilant as they distributed emergency preparedness kits.

Secretary of Defense Donald H. Rumsfeld told relatives and others at Arlington National Cemetery that "the wound that was opened three years ago will always be with us. We know that. Yet our grief has found its purpose. September 11th was a call to arms. And once again, brave men and women have deployed abroad to defend freedom."

It was clear across the region that despite the time that has passed since Sept. 11, 2001, wounds are still fresh.

"Even if it's three years later, I still have the same feeling," said Marinella Hemenway, 36, whose husband, Ronald John Hemenway, an electrical technician, was working at the Pentagon when he was killed.

She was one of about 500 family members at Arlington who mourned openly and together under blue skies that carried wisps of gray. But for Hemenway, crying represents progress. For the first year after the attacks, she stifled her tears, the shock of losing her husband so great, the emotions so overwhelming.

Her daughter, Desiree, now 3, is just now starting to understand that she doesn't have a father. "I miss my daddy," she cried as she got ready for bed recently.

"I don't even know if she remembers him," Hemenway said. "But there are pictures of him all over the house."

Kelly Jackson remembers the day all too well. She remembers her mother's instructions to go to their home in Lanham and wait for her father, Jimmie I. Holley, a Pentagon accountant, to call, and how the hours passed without a word.

Yesterday, Jackson was strong all through the early morning, even as she and family members placed flowers on Holley's grave. Then, at 9:37 a.m., during a moment of silence noting the time American Airlines Flight 77 crashed into the west side of the Pentagon, the tears came. They continued through the speeches, until Jackson's 6-year-old daughter, Kayla, took a tissue and wiped her mother's eyes.

In addition to the scripted pageantry in Arlington and New York, there were smaller, more intimate ceremonies.

"This year, the family members wanted a quiet observance," said Montgomery County Executive Douglas M. Duncan, who joined about 50 people in Rockville's Courthouse Square Park at a memorial for 11 local victims. "There are no speeches. It's just a day to be with the family members and offer a silent prayer."

Many of the relatives who attended had helped select the memorial's design, a semicircle of 11 benches, each inscribed with the signature of one of those who was killed. Parents, widows and children took turns placing white roses on the benches. Then they stood before a modest stainless steel column watching the morning sun light up each name engraved on a bronze plaque. Many wore small, Pentagon-shaped lapel pins bearing the infamous date.

Several said this anniversary was more difficult than the previous ones, in part because of the conflict in Iraq.

"It just feels so devastating this year," said Carole Reuben, whose son, Todd, was aboard the plane that crashed into the Pentagon. "Maybe it's because there's been so much in the news, with the election coming up and more than 1,000 killed in Iraq. We were in a cocoon before, and now it seems the cocoon has been penetrated."

Although family members hugged each other and took comfort in being with others who understood their suffering, several also said that the commemorations inevitably cause more pain.

"You think you're healed, and it brings the scab off," said Marilyn Pontell, whose son, Darin, a lieutenant in naval intelligence, died at the Pentagon.

The emotions of the anniversary hit some unexpectedly. While leading a morning tour of Washington National Cathedral, Andrew Bittner suddenly found himself wiping away tears as he pointed out a small white stone cross on a pedestal. It was fashioned from fragments of the Pentagon's facade.

The cathedral has played an integral part since the attacks. Bishop Desmond Tutu spoke there on its first anniversary. The Dalai Lama took the lectern on the second. Three days after the attacks, President Bush stood in the cathedral and declared: "This nation is peaceful, but fierce when stirred to anger. This conflict was begun on the timing and terms of others. It will end in a way and at an hour of our choosing."

Yesterday, though, the mood was much more subdued, as Bishop John Bryson Chane, standing just a few feet from where Bush had spoken, struck a softer tone. "The war on terrorism cannot be won if we see it as a war," he said. "For war is the ultimate definition of human failure."

He urged about 300 congregants to "think beyond revenge, war and getting even." And he added that on Sept. 11, 2001, "God was there in the ashes and horror of it all, and in the hearts, minds and souls of those who came to the aid of their fellow workers, friends and citizens."

Judy Taylor of Rockville was among those listening to him. She worked as a concierge in the first-class lounge at Dulles International Airport but retired shortly after the 9/11 attacks, unable to cope. Yesterday, Taylor wore her old United uniform and a black armband with the logos and numbers of the four flights that went down that day -- American Airlines Flights 11 and 77 and United Flights 93 and 175.

"As I walked into church, I was thinking of all those 3,000 innocent souls in heaven," she said.

Then she dabbed at her eyes, pointed to the flight numbers on her armband and said, "Make sure you write down the numbers, so people won't forget."

As the country wrapped itself in communal grief yesterday, some simply wanted to mourn alone.

April Gallop of Woodbridge, who survived the attack on the Pentagon, said the day should be sacrosanct, not a spectacle. "It's not a show," she said. "It's not a [public relations] campaign. It's a serious and solemn time."

"I'm going to stay home and kiss my son," she said.

John Milton Wesley of Columbia just wanted space and stillness to remember fiancee Sarah M. Clark, a teacher at Backus Middle School in the District who was on the plane that hit the Pentagon. "I just want some quiet time," he said.

Yesterday morning, he hiked the trail they used to walk together and then went home to continue the task that only last week he could bear to begin: He cleaned out her dresser drawers.

The clothes were still folded neatly, just as Clark had left them three years ago. Even the soaps to make her clothes smell nice were still there. And when he opened the drawers, the scents wafted out -- lilac and violet, her favorites.

At Arlington National Cemetery was An Nguyen, 7, whose father, Khang Nguyen, died at the Pentagon."Tribute in Light," a symbol of both loss and hope, marks the spot in New York where the twin towers once stood.

Anna Norcia, 17, left, and Nicole Williams, 18, both of New Jersey, made a sunrise visit to Shanksville, Pa.At Arlington Cemetery, Cynthia Droz, center, is comforted at the tombstone of her husband, Charles Droz, who was aboard the plane that hit the Pentagon.