JEWEL SAMAD/AFP/Getty Images(NEW YORK) -- There will be numerous events around the nation Sunday to commemorate the 10th anniversary of the Sept. 11, 2001 terror attacks on the World Trade Center, the Pentagon, and the crash of United Flight 93 in a field in western Pennsylvania.
President Obama and first lady Michelle Obama will attend the tributes to honor the dead in New York, Washington, D.C., and Shanksville, Pa., though -- for security reasons -- the exact times of their appearances have not been made public.
In New York City, the observances at the World Trade Center site will begin with a moment of silence at 8:46 a.m. -- the time the first plane hit the north tower. There will be three other moments of silence to commemorate the time the second plane hit the south tower and the times each tower fell.
With families of the WTC victims invited to the event, the National 9/11 Memorial will also be dedicated on Sunday and opened to the public the following day. The signature features of the 9/11 Memorial are the 2,983 names of the dead etched into bronze panels and two waterfalls cascading down into twin reflecting pools within the footprints of the towers.
At sunset, the skies will be lit up with the “Tribute in Light” -- 44 7,000-watt xenon light bulbs that will form two 48-foot squares to resemble the shape and orientation of the towers. The “Tribute in Light” will be visible from 30 miles away.
President Obama plans to visit Shanksville on Sunday for the ceremony to honor the passengers of United Flight 93, who died while preventing the hijackers from flying the plane into either the Capitol or the White House. The day before, Vice President Joe Biden will help dedicate a memorial for the victims at the site of the crash.
The president, who will also attend a ceremony at the Pentagon, will conclude the day’s events by attending an interfaith prayer service and delivering remarks at the Washington National Cathedral.
Copyright 2011 ABC News Radio
