Larry Moore of East Freedom, Pennsylvania, writes a note on a sign that reads, "I did not forget," on a hillside above the United Airlines Flight 93 crash site from the 9/11 attacks in Shanksville, Pennsylvania May 2, 2011. [Photo/Agencies]

Newspaper front pages and United States flags left by visitors are seen at a temporary memorial on a hillside above the United Airlines Flight 93 crash site from the 9/11 attacks in Shanksville, Pennsylvania May 2, 2011. [Photo/Agencies]