The mayor said two promises were made to the city after the World Trade Center was destroyed -- to capture or kill bin Laden and to rebuild at the site, The Wall Street Journal reported. As Bloomberg spoke, construction work continued on the Freedom Tower.
"Osama bin Laden is dead, and the World Trade Center site is teeming with new life," Bloomberg said.
Crowds began gathering at Ground Zero late Sunday and early Monday. In Times Square. Rudolph Giuliani, who was mayor in 2001, said the celebratory atmosphere in the small hours made him "feel a little strange."
"Nothing erases the loss of all those lives," he said.
A steady stream of people visited the memorial at the Pentagon in Arlington, Va., The Baltimore Sun reported. Gary and Nancy Cotton, who lost a close friend there, left pink carnations and a copy of The Washington Post on top of a bench bearing the name of Sheila Hein of College Park, Md., a Navy photographer.
"We had to do something," Cotton said. "That's kind of like what it boils down to. You can't just watch television."
In Shanksville, Pa., where United Flight 93 crashed after passengers tried to retake the plane, cards, flags and newspaper front pages adorned the chain link site around the crash site, The (Newark, N.J.) Star-Ledger reported. Many of those who visited the site, where a memorial is planned, were strangers who happened to be driving through western Pennsylvania.
"I felt like I had to stop," said Ed Boots, who had been behind the wheel for 8 hours driving from North Carolina to his home near Pittsburgh.
Celebrity Families of 2014 [PHOTOS]