SHANKSVILLE, Pa. -- Golden bells tolled 40 times yesterday on the field in Somerset County where United Flight 93 crashed eight years ago, commemorating the 40 passengers and crew members who died trying to wrest the plane from hijackers.

Jerry Bingham drove more than 400 miles in his motor home -- as he does every year -- to hear the sounds of two bells mark his son's name: first a low, baleful tone, then a clear chime.

"We can't forget what happened on that plane," said Mr. Bingham. "My son and 39 other people were heroes."

Wearing an American flag-patterned tie and an American flag pin on his corduroy blazer, Mr. Bingham listened to the voices of officials and clergy fill the rolling hills around him.

"As much as we may try, we can never truly grasp the emotions that must have gone through the hearts of the passengers and crew members," said retired Gen. Colin L. Powell, who was secretary of state on Sept. 11, 2001. "It was up to them, alone and unarmed. They seized the moment, and they lost their lives in so doing."

Mr. Bingham said his son, Mark Bingham, was a courageous and talented 31-year-old. "The type of person you don't forget," he said.

He was traveling to California, where he ran a public relations firm, when Flight 93 was hijacked near Cleveland.

The plane, which was scheduled to fly from Newark, N.J. to San Francisco, abruptly changed course toward Washington, D.C., where another plane had crashed into the Pentagon.

Passengers and crew members heard of the other terrorist attacks that morning via cell phone and struggled to re-take the plane.

The 9/11 Commission concluded that the hijackers downed the plane in Pennsylvania as the hostages revolted. Flight 93 crashed in Shanksville shortly after 10 a.m.

"It was the first battle in the war on terror," said U.S. Rep. Bill Shuster, R-Blair, who spoke at the commemoration yesterday.

Speakers included former governor and U.S. Secretary of Homeland Security Tom Ridge, U.S. Secretary of the Interior Ken Salazar and retired Gen. Tommy Franks.

Gov. Ed Rendell promised that the long-delayed Flight 93 memorial will be completed by the 10th anniversary of the crash in 2011. Work is expected to begin this fall.

"The hills where the heroes of Flight 93 perished are a hallowed ground," said Mr. Salazar.

"I feel closer to her here," said Christine Fraser, whose sister, Colleen L. Fraser, a 51-year-old advocate for the disabled, died in the crash.

For Ilse Homer, the pilgrimage to Shanksville is a way to keep her son's memory alive.

She drove 71/2 hours from her home in Long Island to honor her son, LeRoy W. Homer Jr., Flight 93's co-pilot.

"We know that his ashes are here and his spirit is here," said Ms. Homer.

Her son had served in the Air Force for eight years before becoming a pilot for United Airlines. He was 36 when he died.

"We wonder about a lot of things," said Germaine Wilson, LeRoy Homer's sister. "He had a 10-month-old daughter named Laurel. These are the Laurel Highlands. We don't know if it was destiny, fate."

As speakers extolled the sacrifice of those who died, rows of visitors leaned over a metal fence to catch their words. The crowd was filled with solemn faces and American flags: on T-shirts, jackets and scarves and held in hands.

After the ceremony, family members of the victims filed into a reception, greeting one another.

For eight years, Mr. Bingham has grown to know the people who share his loss, and this year, in the field where his son died, a memorial will begin to rise.

"We feel like things happen for a reason," he said.