Morning rain cleared and on a cool and cloudy Saturday afternoon outside Shanksville, Pa., a stone wall etched with the names of the 40 people who died aboard United Airlines Flight 93 on Sept. 11, 2001, was unveiled in somber silence.

Vice President Joe Biden and former Presidents Bill Clinton and George W. Bush were among the thousands who gathered to dedicate a memorial at the site of the flight’s crash a decade ago.

“They didn’t know the horror that awaited,” Biden said of the passengers and crew who fought off a hijacking attempt believed to be directed at the U.S. Capitol. “They confronted unimaginable fear and terror with a courage that has been summoned only by the truest and the rarest of American heroes.”

Clinton made news, saying that he was “aghast” to learn that $10 million still needs to be raised to complete the memorial, and that he and House Speaker John Boehner (R-Ohio), who attended the ceremony with a congressional delegation, would work together to raise it. “Let’s get this show on the road. Let’s roll,” the former president said, invoking a line used by one of the passengers aboard the flight who fought off hijackers.

Interior Secretary Ken Salazar said the memorial will be “an enduring monument to love, courage and sacrifice.” Salazar also read a letter signed by former President Jimmy Carter.

“We know and I know that no memorial, no words and no acts can fill the void that they left in your hearts,” Biden said. “We are not here to unlive history; we are here to honor those whose courage made history and is going to inspire generations of Americans to come.”

In his speech, Bush looked back on the destruction that took place in New York, Washington and Shanksville 10 years ago.

“With the distance of a decade, 9/11 can feel like a part of a different era, but for the families of the men and women stolen, some of whom join us today, that day will never feel like history,” Bush said. “America shares your grief, we pray for your comfort and we honor your loved ones.”

“One of the lessons of 9/11 is that evil is real, and so is courage,” he said.

Clinton offered thanks to Bush, President Barack Obama, Biden and those who work with them “for keeping us from being attacked again.” Biden thanked Bush “for making it clear that America could not be brought to her knees and for helping us stand tall and strike back.”

The Boeing 757 was headed from Newark to San Francisco when Al Qaeda operatives wrested control away from the pilot. But passengers and crew aboard the flight fought back and are credited with diverting the plane from what’s believed to be the hijackers’ intended target — the U.S. Capitol dome in Washington — into the field in rural Pennsylvania.

“Americans are alive today because the passengers and crew of Flight 93 chose to act, and our nation will be forever grateful,” Bush said. They left “a legacy of bravery and selflessness that will always inspire Americans.”

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