"You're looking at steel that was bent, most likely, from the force of the collapse," said Alice Greenwald, director of the World Trade Center Museum.
But 15 miles away, hidden inside an 80,000-square-foot hangar at New York's JFK Airport, is the largest collection of precious pieces from that fateful day, CBS News correspondent Michelle Miller reports.
Construction workers saved these artifacts while removing nearly two million tons of debris.
Alice Greenwald gets chills every time she walks into the building. As director of the World Trade Center Museum, she'll place these artifacts in an official memorial when it opens in 2011.
"We have an obligation - a moral obligation, an obligation of our citizenry, an obligation of just human beings - to remember them," Greenwald said.
The most familiar relic is the last steel column removed from ground zero, preserved with pictures and messages still intact.
"You have on here messages to people who are gone - you have thank-yous to people who were there," Greenwald said. "It's a real symbol of the way the world came together on 9/11," she said.
More first responders died on 9/11 than on any other single day in history.
Looking at a burned-out fire truck, Miller asked: "Is this the front?"
"The front - you can barely see the door of the cab," Greenwald said.
Half of the fire truck was parked under a bridge, protected. The other half was incinerated.
"When I look at this truck, it's almost a metaphor of the serendipity that day," Greenwald said. "Where you were determined whether you lived or died."
While so many lives were lost, incredibly, many personal belongings survived: The shoes that carried Florence Jones to safety; Robert Gschaars' work ID and wedding band; Patricia Fagan's purse with her favorite pink lipstick.
"People got so little back of their loved ones, and so anything, whether it was a Citibank swipe card or a rosary bead or a wallet, they knew that coming back would come to have palpable meaning," said Jan Ramirez.
Ordinary items with extraordinary meaning to a nation that can be shared when the memorial is complete.