Flight 93 National Memorial (U.S. National Park Service)
(Photo Credit: Nicholas Kamm/AFP/Getty Images)
Courtney Peller (L), 14, Taylor Duffy (C) and Caitlin Rakowski, both 15, look at the field in Shanksville, on Sept. 9, 2011, where United flight 93 crashed on Sept. 11, 2001. The US prepares to mark the tenth anniversary of the Sept. 11, 2001 attacks.