Solemn memorials are being held in New York, Washington and Pennsylvania among other places to honor the victims of the September 11, 2001 terror attacks.
Civil War re-enactor Cpl. Robert Fuller Houston with the 3rd Regiment Infantry, lowers his head during a prayer at a ceremony, Sept. 11, 2013, marking the 12th anniversary of the 9/11 terrorist attacks at the Betsy Ross House in Philadelphia.
The sun reflects off the stainless steel wall of the "Empty Sky" memorial to New Jersey's victims of the Sept. 11, 2001 terrorist attacks, Sept. 11, 2013, in Jersey City, N.J.
Detroit Fire Department Lt. Gerod Funderburg rings a bell during a ceremony in Detroit, Sept. 11, 2013, marking the 12th anniversary of the 9/11 terrorist attacks.
Red roses are placed next to names of victims of the Sept. 11, 2001 terrorist attacks on the U.S. at a memorial site during a ceremony marking the 12th anniversary of 9/11 outside Jerusalem, Sept. 11, 2013.