Solemn memorials are being held in New York, Washington and Pennsylvania to honor the victims of the September 11, 2001 terror attacks.
A man walks through the 9/11 Empty Sky memorial at sunrise across from New York's Lower Manhattan and One World Trade Center in Liberty State Park in Jersey City, New Jersey, September 11, 2013.
FDNY Firefighter Mike Bellantoni of New York prepares a memento at the Firefighter's Memorial adjacent to the World Trade Center, Sept. 11, 2013 before the start of the official ceremonies at the 9/11 Memorial nearby.
Britain's Prince Harry (L) and Prince William (R) take part in a trade on the trading floor of BGC Partners. BGC holds a Charity Day each year to commemorate the 658 employees who lost their lives in the 9/11 attacks on the World Trade Centre in New York. London, September 11, 2013.
Former Mayor Rudy Giuliani (2nd L) and New York City Mayor Michael Bloomberg (2nd R) attend a ceremony at the 9/11 Memorial marking the 12th anniversary of the attacks on the World Trade Center in New York September 11, 2013.