President Barack Obama laid a wreath at Ground Zero Thursday, paying tribute to victims of the Sept. 11, 2001, terrorist attack in New York.

It was his first trip to the site since his election. White House spokesman Jay Carney said on Wednesday that it would be “a cathartic moment for the American people” now that Osama bin Laden is no longer a threat.

During the three hours that he will spend in New York, the president will meet privately with 9/11 families and first responders who rallied to the rescue in 2001, as well as Mayor Michael Bloomberg and former Mayor Rudy Giuliani. Obama also will participate in a wreath-laying ceremony. He did not deliver a speech.

One person who was noticeably absent is Obama’s predecessor President George W. Bush, who declined an invitation to join him, even though the terrorist attacks and the resulting wars in Iraq and Afghanistan largely defined his presidency.

“He appreciated the invite, but has chosen in his post-presidency to remain largely out of the spotlight,” a Bush spokesman said.

(Photo:  AP Photo/Charles Dharapak)