At Ground Zero, the names took precedence, 2,801 of them read aloud, from Gordon Aamoth Jr. to Igor Zukelman. Patriotic resolve held sway at the Pentagon. And in a field near Shanksville, Pa., grief was partially offset by pride.

At each of the three sites, and in communities across the nation and world Wednesday, Americans and their allies relived the staggering events of one year ago and remembered those who died.

"For those who lost loved ones, it has been a year of sorrow, of empty places, of newborn children who will never know their fathers here on earth," President Bush said in an evening speech to the nation, delivered from Ellis Island with the Statue of Liberty as a backdrop.

Bush acknowledged that Americans no longer felt invulnerable to their enemies' attack, but vowed a relentless quest for justice and security.

"What our enemies have begun, we will finish," he said.

At the World Trade Center, the roll call of the dead and missing began after a moment of silence at 8:46 a.m., the time when the first terrorist-piloted plane struck. It took 2 1/2 hours -- 50 minutes longer than planned -- for 197 readers to complete the list of names.

"They were our neighbors, our husbands, our children, our sisters, our brothers and our wives. They were our countrymen and our friends. They were us," New York Mayor Michael Bloomberg told grieving families. Later, at the nearby site of an interim memorial, he lit an eternal flame, saying, "The memories of those we lost will burn with unending brightness."

While wistful cello music accompanied the ground zero ceremony, a booming rendition of the national anthem set the tone for morning commemorations at the Pentagon, where 184 people died when American Flight 77 smashed into the building.

Bush presided at the Pentagon ceremony, then flew to southwest Pennsylvania to help honor the 40 people killed when United Flight 93 crashed in a field near Shanksville. The passengers and crew were hailed by Homeland Security Director Tom Ridge as heroic "citizen-soldiers" for struggling to take back their hijacked plane and avert a possible attack on the Capitol or White House.

"If we learn nothing else from this tragedy, we learn that life is short and there is no time for hate," said Sandy Dahl, the wife of Flight 93 pilot Jason Dahl.

Bush laid a wreath in Shanksville, then another at Ground Zero after an afternoon flight to New York. Carrying the badge of a fallen Port Authority police officer, the president and first lady Laura Bush lingered at the site for nearly two hours, greeting and comforting relatives of Sept. 11 victims.

Pauses to remember

Many Americans went to work or to school, but it was far from business as usual. Telemarketers cut back on their phone calls, politicians kept their campaign ads off the air, some dealers at a casino in Reno, Nev., even held their cards for a moment in a gesture of respect.

Major League Baseball called for a moment of silence at 9:11 p.m. local time at all night games. Before the New York Yankees' home game with Baltimore, a memorial inscribed "We Remember" was unveiled in Monument Park beyond the center field fence.

Though the government had raised the terror alert to its second highest level, based on new information of possible strikes, no serious incidents were reported.

Federal officials told Americans to go ahead with their plans for the day, but many were apprehensive about boarding airplanes. A spokeswoman at Atlanta's Hartsfield International Airport, one of the country's busiest, estimated that passenger traffic was down more than 50 percent.

In New York, thousands of mourners gathered at the dusty site of the trade center, clutching pictures of the dead and placing roses around a "circle of honor."

The first person to take a turn reading the names was Rudolph Giuliani, who as mayor was praised for his steady leadership in the days after Sept. 11. Following him as readers were survivors of the attack, relatives of those who died, New York Sen. Hillary Rodham Clinton and actor Robert De Niro.

Marianne Keane, 17, whose stepfather Franco Lalama died in the attack, spoke briefly.

"I would give anything to go back to the morning of Sept. 11 and tell him how much I appreciated everything he's done for me," she said. "But I think he knows that now. In my eyes, he died a hero."

As the ceremony proceeded, a camouflaged military helicopter with a protruding gun turret circled overhead, while snipers and tactical units kept watch.