SHANKSVILLE, Pa. (AP) - Thousands of family members and friends of the 40 passengers and crew killed aboard United Flight 93 were gathering with political dignitaries, local officials and residents for a second day at the newly dedicated national park that marks the site where the hijacked jet crashed during the Sept. 11, 2001 terrorist attacks.
Sunday's memorial service at the Flight 93 Memorial, about 60 miles southeast of Pittsburgh, was being held in concert with ceremonies in New York City and Washington, D.C., where other hijacked jets crashed into both towers of the World Trade Center and the Pentagon.
Vice President Joe Biden and former presidents Bill Clinton and George W. Bush were on hand Saturday to christen the Flight 93 Memorial, the nation's newest national park.
President Barack Obama participated in the memorial service in New York City and is scheduled to visit the Flight 93 site on Sunday. It's not clear whether Obama will speak during the ceremony, but he is expected to lay a wreath at the memorial following the ceremony and meet with family members of those who perished, according to Gov. Tom Corbett's staff.
Visitors to the Flight 93 service observed moments of silence at 8:46 a.m. and 9:03 a.m. -- the times when two other airliners were crashed into New York's twin towers. They were expected to do the same at 9:37 a.m., when a third airliner hit the Pentagon.
The Flight 93 program was to begin a few moments later before a fourth -- and final -- moment of silence is observed at 10:03 a.m.
That's when Flight 93 crashed after passengers and crew, some alerted by cell phone calls from loved ones about the New York attacks, decided to try to wrest control of their plane from four hijackers. The plane crashed during the struggle, and investigators later determined the hijackers intended to crash it into the Capitol in Washington, D.C., where the House and Senate were in session that morning.
Those actions prompted Biden and others on hand Saturday to salute the Flight 93 victims as "citizen patriots" who fought the first battle in the ongoing war against global terrorism.
By contrast, Sunday's memorial was expected to take a more somber tone, low-key tone as some of Pennsylvania's Congressional delegation was expected to join Corbett and former Gov. Tom Ridge to honor the dead. Ridge was in office when the attacks occurred and later became the country's first secretary of Homeland Security.
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