Across the country, Americans are marking the second anniversary of the September 11 terrorist attacks Thursday.
At the World Trade Center in New York, 200 children are taking turns reading aloud the names of the nearly 3,000 people killed in the attacks. The children all have relatives among the dead.
At sunset, two beams of light pointing skyward will be switched on, evoking the image of the twin towers.
At the White House in Washington, President Bush led a moment of silence at 8:46 a.m., the exact time the first hijacked plane slammed into the north tower of New York's World Trade Center. Earlier, the president attended a multi-denominational prayer service to remember the victims.
Ceremonies are also taking place at the Pentagon, where more than 180 people were killed when a third hijacked plane slammed into the building. And services will be held in a field in Pennsylvania, where the fourth hijacked airliner slammed into the ground, killing all aboard.
Other ceremonies will be held in the state of Pennsylvania, where a fourth hijacked airliner slammed into a field, killing all 40 passengers and crew.
The president is not attending the ceremonies in New York or Pennsylvania.
Services across the country will feature the tolling of bells, the laying of wreaths, and in many places, moments with no words at all.
Wednesday, Mr. Bush called for tougher legal measures to fight terrorism in the United States. He urged Congress to pass legislation giving law enforcement officers the same tools to fight terrorists that they use against other criminals - such as drug traffickers and mobsters.
Vice President Dick Cheney will represent the White House in New York, but will not attend a ceremony at the site of the downed twin towers at the request of city officials, who said the extra security would inconvenience the victim's families.
Secretary of Defense Donald Rumsfeld will preside over a wreath laying and other commemorative events at Arlington National Cemetery and the Pentagon.