By Daniel Lovering
SHANKSVILLE, Pa (Reuters) - Thousands gathered Sunday at the site where hijacked United Airlines Flight 93 crashed as the nation paused to mark the 10th anniversary of the September 11 attacks that killed nearly 3,000 people -- including 40 passengers and crew here.
By 10:03 a.m. -- the moment when the Boeing 757 passenger jet slammed into the field in southwestern Pennsylvania here back in 2001 -- the sun had burned through the fog that had covered the hills earlier in the morning, warming the faces of those who marked the anniversary.
President Barack Obama, who was in New York to remember the nearly 2,700 people killed at the World Trade Center in the coordinated attacks 10 years ago, arrived in Shanksville at midday Sunday to lay a wreath at the memorial.
The president and the first lady, Michelle Obama, walked to the boulder that marks the approximate site where the airplane crashed and then spent about 45 minutes talking with family members of the passengers and crew members who died.
Flight 93, bound for San Francisco from Newark, New Jersey, never hit its intended target -- investigators believe the hijackers were planning to crash into either the U.S. Capitol or the White House -- because some of the passengers stormed the cockpit and attempted, unsuccessfully, to regain control of the aircraft.
Pennsylvania Governor Tom Corbett said their actions, which caused the plane to crash, "set a new standard for American bravery."
Paul Greengrass, who directed a feature film about Flight 93, said the passengers' achievement seems even more extraordinary today than it was a decade ago.
"It's just unimaginable that 10 years ago today, just above your heads, in this peaceful scene was a struggle of that importance and magnitude," Greengrass said.
Ray VanSickle, 45, of Uniontown, Pennsylvania, said, "I wasn't connected with anybody on the flight but connected as an American, as someone who felt a lot of pain."
"As I see the family members and friends come in, I can't imagine what they went through," said VanSickle, a high school Spanish teacher. "I need to be here, I think."
A private ceremony will be held on Monday for relatives of the victims to bury three caskets containing unidentified human remains from the crash, said Patrick White, whose cousin "Joey" Louis Nacke died aboard Flight 93.
"It will be equally as solemn and more subdued certainly than today but probably far more emotional in its impact," he said. "For me it's the most appropriate reuniting of the passengers and crew in their final resting place."
Somerset County Coroner Wally Miller wiped away tears before speaking, repeating the refrain, "We remember them."
The memorial is about 40 percent complete. It includes a marble wall etched with the names of the 40 passengers and crew that follows the flight path and the boulder marker.
The memorial is scheduled to be finished in 2014, according to architect Paul Murdoch. Plans call for 40 groves of trees to be planted in a nearby field, with a walkway along the groves to pass between two large walls. An overlook to allow visitors to see the expanse of the field and the crash site also is planned.
Organizers say $10 million still needs to be raised to complete the Flight 93 National Memorial. About $52 million has already been raised in public and private funds.
At the ceremony on Saturday, former President Bill Clinton, a Democrat, said he and House Speaker John Boehner, a Republican, had agreed to have a bipartisan event to raise money for the memorial.
(Editing by James B. Kelleher and David Bailey)