A woman grieves at her husband's inscribed name at the edge of the North Pool during memorial observances on the 13th anniversary of the 911 attacks.
U.S. President Barack Obama, U.S. first lady Michelle Obama and Vice President Joe Biden observe a moment of silence on the 13th anniversary of the 9/11 attacks at the White House in Washington Politicians, dignitaries and victims' relatives were gathering in New York, Washington and Pennsylvania on Thursday to commemorate the nearly 3,000 people killed in al Qaeda's attack on the United States 13 years ago on Sept. 11.
Sam Pulia, mayor of Westerchester, Illinois, and a former police officer of the same town, salutes the name of his cousin, New York firefighter Thomas Anthony Casoria, who was killed in the South Tower.
Visitors to the Flight 93 National Memorial in Shanksville, Pa., listen as the names of the 40 passengers and crew of Flight 93 are read during a Service of Remembrance at the Flight 93 National Memorial.
White roses are seen placed in an inscribed name along the edge of the North Pool during memorial observances on the 13th anniversary of the 911 attacks at the site of the World Trade Center in New York.
Members of the New York Police Department, Fire Department of New York and Port Authority Police Department carry an American flag at the beginning of the memorial observances held at the site of the World Trade Center.
Paola Braut, of Belgium, kisses a photograph of her son Patrice along the edge of the North Pool during memorial observances held at the site of the World Trade Center.
Family and friends of the 40 passengers and crew of Flight 93 walk past the Wall of Names at the Flight 93 National Memorial in Shanksville, Pa., as they arrive for a Service of Remembrance Thurs.
A single rose is seen on inscribed names on the edge of the north pool of the 911 Memorial.
President Barack Obama, U.S. first lady Michelle Obama and Vice President Joe Biden observe a moment of silence on the 13th anniversary of the 9/11 attacks.
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