"This Sunday, the nation marks the 10th anniversary of 9/11, the worst terrorist attack in the history of the United States," Panetta said Tuesday. "We will honor those who died at the Pentagon, 184 of them, but I thought it was also appropriate to come here and honor those -- nearly 3,000 -- who died here in New York City."
Panetta is the first Cabinet officer to visit the site where two hijacked airplanes plowed into the World Trade Center twin towers on Sept. 11, 2001, the Pentagon said in a release. He was accompanied by New York Mayor Michael Bloomberg.
The area where the towers once stood will open as part of the memorial Sunday as part of the events marking the day terrorist hijackers crashing four passenger jets -- one into each of the towers, one into the Pentagon, and one into a field near Shanksville, Pa., short of a likely target in Washington. The commandeered plane crashed in Pennsylvania after passengers rushed the hijackers.
The terrorist attacks united the nation in its commitment that such horror "will never happen again," Panetta said.
"As tragic as 9/11 was, we have drawn tremendous inspiration [from it]," the Pentagon chief said.
Panetta was to travel from New York to Shanksville to visit the Flight 93 Memorial there, but had to cancel because of weather.
Celebrity Families of 2014 [PHOTOS]