SHANKSVILLE, Pa. -- Under a brilliant midday sun yesterday, a simple ceremony marked the groundbreaking for a permanent national memorial on the site where United Airlines Flight 93 crashed into a field on Sept. 11, 2001, killing everyone aboard.

"In honor of the 40 American heroes who gave their lives here ... Let's roll!" said U.S. Interior Secretary Ken Salazar as he dug a silver shovel into a mound of dirt.

He echoed the famous words shouted by Todd Beamer before the passengers and crew of Flight 93 attempted to retake the plane from hijackers as it headed toward Washington, D.C.

More than eight years after the terrorist attacks, work is ready to begin on a 2,200-acre, $60 million park in Somerset County, which already hosts a temporary memorial that has attracted as many as 1 million visitors.

Federal officials have set Sept. 11, 2011, as the deadline to finish the first phase of the project.

Dozens of family members of Flight 93 passengers had been pushing for yesterday's event to happen.

"We made it," said Gordon Felt, president of Families of Flight 93, whose brother Edward had been on the plane. "We made it -- not to our goal, not to the finish line, certainly not to any semblance of closure. But, nevertheless, we made it to the next milestone on our journey."

During the ceremony, a group of 40 elected officials, relatives of passengers, and emergency responders plunged shovels into the dirt, within eyeshot of a fenced-off area where the plane hit the ground.

Four younger relatives stood at the front of the group: Justin Nacke, nephew of passenger Louis Nacke; Sarah Wainio, sister of passenger Elizabeth Wainio; and Campbell and Peyton Peterson, whose grandparents, Donald and Jean Peterson, were on the flight.

"This has been a long time coming," said Justin Nacke, 21, of Baltimore.

The memorial project has encountered obstacles, but momentum started to build this year when the federal government reached agreements with all of the landowners of properties needed to build a park.

Yesterday, Mr. Salazar announced that Arrow Kinsley of York, Pa., will be the principal contractor for the first construction phase.

The phase will focus on the "sacred ground" where the plane came down. A plaza made of concrete with black granite stone will allow visitors to walk up to the edge of the crash site, but only family members and park officials will be able to enter.

The names of all 40 passengers and crew members will be engraved in white marble on a wall.

The second phase will include the creation of 40 memorial tree groves, and a third phase will bring more trees and a tower with 40 wind chimes. The tower will be built near Route 30, the main roadway approaching the park.

In total, the park will have as many as 140,000 trees, according to Paul Murdoch, the project's architect.

"It feels good to go through this challenge," he said after yesterday's groundbreaking.

Yet there are still many challenges ahead for the park. It's unclear when the second and third phases will be completed, and fundraising is still under way.

Of the project's $60 million price tag, half is slated to come from private donations. The federal and state governments will cover the rest.

So far, $16 million has been raised, including all of the funds needed for the first construction phase, according to Neil Mulholland, president and CEO of the National Park Foundation.

He said the goal is to raise $30 million in private funds by the 10th anniversary of Sept. 11.

Over 50,000 people have donated so far, and Mr. Mulholland hopes yesterday's groundbreaking will attract many more donors.

"People want to donate to something tangible," he said.

Flight 93 was on its way from Newark, N.J., to San Francisco on the morning of Sept. 11 when it was hijacked near Cleveland. The plane abruptly changed course, headed for Washington, D.C., where another plane had already crashed into the Pentagon.

The Boeing 757 went down just after 10 a.m. into a reclaimed strip mine in Somerset County.

Since then, Mr. Felt has come to Shanksville from central New York "too many times to count" to be near the remains of his oldest brother.

Edward Felt, 41, lived in Matawan, N.J., and left behind a wife and two children. A software engineer, he was on a business trip on Sept. 11.

"We continue to be inspired by the selfless acts of the crew and passengers of Flight 93," Gordon Felt said from a makeshift podium. "History lives on this site."

Some of the event's participants were too young to remember what happened on Sept. 11, including 13-year-old Campbell Peterson, who was in kindergarten at the time. Yesterday, he and his younger brother had a chance to wield shovels alongside Mr. Salazar, Gov. Ed Rendell and U.S. Sen. Bob Casey.

"It feels very good to be here," said Campbell, who lives in Bethesda, Md..

Mr. Rendell said the state has already contributed more than $10 million to the project, and the Pennsylvania Department of Transportation will contribute another $8.5 million to complete an access road from Route 30.

"This memorial also has to be a teaching memorial," he said. "A memorial that teaches Americans and others from around the world what happened on Flight 93, the heroism of ordinary citizens."

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