Flight 93 Memorial: Shanksville, Pa.

Construction continues in the plaza area of the permanent Flight 93 Memorial site in Shanksville, Pa., on July 22, 2011. The work and preparation continue for the dedication and opening of the first phase of the memorial in honor of those who perished in the crash of United Flight 93 in the attacks of September 11, 2001. In one sense, Shanksville is a tiny village far from major cities and cultural attractions. But the crash of Flight 93 in a field there on Sept. 11, 2001 has brought visitors from around the world to the national park site that now marks the spot where the hijacked plane came down.

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Visitors to the temporary Flight 93 memorial in Shanksville, Pa., look out over a grove of sweet gum trees donated by the organizers of the Sept. 11 Memorial in New York. — AP Photo/Gene J. Puskar

Visitors to the temporary Flight 93 memorial in Shanksville, Pa., on Aug. 1, 2011, look out over a grove of sweet gum trees that were donated to the Flight 93 National Memorial by the organizers of the Sept. 11 Memorial in New York.

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Shanksville: Flight 93 Memorial
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The 17-ton boulder, left, that was placed to mark the site of the crash of Flight 93 at the Flight 93 Memorial in Shanksville, Pa., is shown on Aug. 1, 2011.

Vistor's guides:
Shanksville: Flight 93 Memorial
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Pentagon Memorial

Construction continues at the site of the visitors center at the Flight 93 Memorial in Shanksville, Pa., on June 16, 2011. The first phase of the construction is set to be completed and dedicated on Sept. 10, 2011, one day before the tenth anniversary of the crash of United Flight 93 into a field during the attacks of Sept. 11, 2001.

Vistor's guides:
Shanksville: Flight 93 Memorial
NYC 9/11 sites
Pentagon Memorial

Flags hang on a fence overlooking the crash site of Flight 93 in Shanksville, Pa., on Aug, 1, 2011. In one sense, Shanksville is a tiny village far from major cities and cultural attractions. But the crash of Flight 93 in a field there on Sept. 11, 2001 has brought visitors from around the world to the national park site that now marks the spot where the hijacked plane came down.

Vistor's guides:
Shanksville: Flight 93 Memorial
NYC 9/11 sites
Pentagon Memorial

Lloyd Smith, left, and Laura Sprankle of Hagerstown, Md., visit the overlook at the temporary Flight 93 memorial in Shanksville, Pa. on Aug. 1, 2011. In the background are a grove of sweet gum trees that were donated to the Flight 93 National Memorial by the organizers of the Sept. 11 Memorial in New York. The crash of Flight 93 in a field there on Sept. 11, 2001 has brought visitors from around the world to the national park site that now marks the spot where the hijacked plane came down.

Vistor's guides:
Shanksville: Flight 93 Memorial
NYC 9/11 sites
Pentagon Memorial

A sign describing the plan for the entire Flight 93 memorial is shown on the fence at the temporary memorial as construction continues at the Flight 93 Memorial in Shanksville, Pa. — AP Photo/Keith Srakocic

A sign describing the plan for the entire Flight 93 memorial is shown June 16, 2011, on the fence at the temporary memorial as construction continues at the Flight 93 Memorial in Shanksville, Pa. The first phase of the construction is set to be completed and dedicated on Sept. 10, 2011, one day before the tenth anniversary of the crash of United Flight 93 into a field during the attacks of Sept. 11, 2001.

Vistor's guides:
Shanksville: Flight 93 Memorial
NYC 9/11 sites
Pentagon Memorial

Visitors to the temporary memorial to United Flight 93 overlook the crash site in Shanksville, Pa., on May 2, 2011. In one sense, Shanksville is a tiny village far from major cities and cultural attractions. But the crash of Flight 93 in a field there on Sept. 11, 2001 has brought visitors from around the world to the national park site that now marks the spot where the hijacked plane came down.

Vistor's guides:
Shanksville: Flight 93 Memorial
NYC 9/11 sites
Pentagon Memorial

Former President George W. Bush, former first lady Laura Bush, former President Bill Clinton, Dr. Jill Biden and Vice President Joe Biden review the Wall of Names during the dedication of Phase 1 of the permanent Flight 93 National Memorial near the crash site of Flight 93 in Shanksville, Pa., Saturday, Sept. 10, 2011. The Wall of Names features the names of those passengers and crew aboard Flight 93 who died when the hijacked aircraft crashed on 9/11.

Presidents George W. Bush and Bill Clinton, along with Laura Bush, walk past the Wall of Names during the dedication of the Flight 93 memorial in Shanksville, Pennsylvania, on September 10, 2011.

A rain-covered rose is set on the fence at the temporary memorial to Flight 93 near the plane's crash site in Shanksville, Pa. Friday.