On the eve of the 11th anniversary of the terror attacks, Defense Secretary Leon Panetta visited the Flight 93 National Memorial in western Pennsylvania, "the final resting place of American patriots."

Panetta visited the memorial near Shanksville for the first time, the Associated Press reported, paying his respects to the 40 passengers and crew members who died when United Flight 93 crashed on Sept. 11, 2001.

The plane was traveling from Newark, N.J., to San Francisco when it was hijacked by four terrorists. The terrorists are believed to have intended to crash the plane into the White House or the U.S. Capitol, but the jet went down in a field after passengers fought back.

"I came here to Shanksville to extend our nation's gratitude to the heroes of Flight 93 and their families," Panetta said, according to the Pittsburgh Post-Gazette. "At the cost of their own lives they made a faithful decision to fight back and in so doing they prevented an attack on the U.S. Capitol. I am especially grateful to them because on that day I was at the U.S. Capitol."

Panetta was guided by Patrick White, president of Families of Flight 93, from the memorial's entrance to the Wall of Names. White's cousin, Louis Joseph Nacke II, was among the dead. 

On Tuesday, Vice President Joe Biden will deliver the keynote address at the observance. WPXI in Pittsburgh reports. At 10:03 a.m., the moment the flight crashed, the names of passengers and crew members will be read and the Bells of Remembrance will be rung by members of the victims' families and community members who assisted in the aftermath of 9/11.