NEW YORK (AP) - Letters written by Helen Keller. Forty-thousand photographic negatives of John F. Kennedy taken by the president's personal cameraman. Sculptures by Alexander Calder and Auguste Rodin. The 1921 agreement that created the agency that built the World Trade Center.
Besides ending nearly 3,000 lives, destroying planes and reducing buildings to tons of rubble and ash, the Sept. 11, 2001, attacks destroyed tens of thousands of records, irreplaceable historical documents and art.
In some cases, the inventories were destroyed along with the records. And the loss of human life at the time overshadowed the search for lost paper. A decade later, dozens of agencies and archivists say they're still not completely sure what they lost or found, leaving them without much of a guide to piece together missing history.
"You can't get the picture back, because critical pieces are missing," said Kathleen D. Roe, operations director at the New York State Archives and co-chairwoman of the World Trade Center Documentation Project. "And so you can't know what the whole picture looks like."
The picture starts in the seven-building trade center complex. Hijackers flew jetliners into the twin towers on Sept. 11, 2001, which collapsed onto the rest of the complex, which included three smaller office buildings, a Marriott hotel and U.S. Customs. 7 World Trade Center, a skyscraper just north of the twin towers, collapsed that afternoon.
The trade center was home to more than 430 companies, including law firms, manufacturers and financial institutions. Twenty-one libraries were destroyed, including that of The Journal of Commerce. Dozens of federal, state and local government agencies were at the site, including the Equal Employment Opportunity Commission and the Securities and Exchange Commission.
The Central Intelligence Agency had a clandestine office on the 25th floor of 7 World Trade Center, which also housed the city's emergency command center and an outpost of the U.S. Secret Service.
The first tangible losses beyond death were obvious, and massive.
The Cantor Fitzgerald brokerage, where more than 650 employees were killed, owned a trove of drawings and sculptures that included a cast of Rodin's "The Thinker" - which resurfaced briefly after the attacks before mysteriously disappearing again. Fragments of other sculptures also were recovered.
The Ferdinand Gallozzi Library of U.S. Customs Service in 6 World Trade Center held a collection of documents related to U.S. trade dating back to at least the 1840s. And in the same building were nearly 900,000 objects excavated from the Five Points neighborhood of lower Manhattan, a famous working-class slum of the 19th century.
The Kennedy negatives, by photographer Jacques Lowe, had been stowed away in a fireproof vault at 5 World Trade Center, a nine-story building in the complex. Helen Keller International, whose offices burned up when its building, a block from the trade center, was struck by debris, lost a modest archive. Only two books and a bust of Keller survived.
Classified and confidential documents also disappeared at the Pentagon, where American Airlines Flight 77 slammed into it on 9/11.
A private disaster response company, BMS CAT, was hired to help recover materials in the library, where the jet plane's nose came to rest. The company claimed it saved all but 100 volumes. But the recovery limited access to information related to the Soviet invasion of Afghanistan in the 1980s, as the U.S. prepared to launch an attack a month later.
In New York, CIA and Secret Service personnel sifted through debris carted from the trade center to a Staten Island landfill for lost documents, hard drives with classified information and intelligence reports.
Two weeks after the attacks, archivists and librarians gathered at New York University to discuss how to document what was lost, forming the World Trade Center Documentation Task Force. But they received only a handful of responses to survey questions about damaged or destroyed records.
Federal agencies are required by law to report the destruction of records to the U.S. National Archives and Records Administration - but none did. Federal archivists called the failure understandable, given the greater disaster.
After Sept. 11, "agencies did not do precisely what was required vis-'-vis records loss," said David S. Ferriero, the Archivist of the United States, in an email to The Associated Press. "Appropriately, agencies were more concerned with loss of life and rebuilding operations - not managing or preserving records."
He said off-site storage and redundant electronic systems backed up some records; but the attacks spurred the archives agency to emphasize the need for disaster planning to federal records managers.
Said Steven Aftergood, the director of the project on government secrecy at the watchdog group the Federation of American Scientists: "Under extreme circumstances, like those of 9/11, ordinary record keeping procedures will fail. Routine archival practices were never intended to deal with the destruction of entire offices or buildings."
Only the U.S. Attorney's Office of the Southern District formally requested help from federal archivists after discovering stored case files kept had been damaged by mold and water.
The EEOC had to reconstruct 1,500 discrimination case files, said Elizabeth Grossman, supervisory trial attorney for the agency in 2001 at the time of the attacks. Cases were delayed for months. Computers had been backed up only as of Aug. 31, 2001. Witness interviews had to be conducted all over again.
The Port Authority of New York and New Jersey, which owns the region's airports, bridges and the World Trade Center, had much of its archives and the contents of its library - which had closed in 1995 as a cost-cutting measure - in the building.
But a decade later, it only has "a general idea" of what documents were destroyed, Port Authority spokesman Steve Coleman said, including most of its video and photo archives, board meeting minutes and the compact that created the bi-state agency. It was kept on the 67th floor of the north tower.
"We do not have a detailed list" of the missing records, Coleman said in an email. The agency meticulously stores thousands of tons of steel from the building and other wreckage of the trade center in a hangar at Kennedy Airport.
A meeting had been scheduled - on Sept. 11, 2001 - between the agency and a group of libraries that had wanted to claim parts of the Port Authority collection, stored in the north tower. The meeting had been postponed at the last minute, said Ronald Becker, the head of special collections at Rutgers University Libraries, who was supposed to attend.
Not everything was lost. Copies of inventories had been sent out to the libraries that had sought to take parts of the collection, and as workers sifted through the rubble at ground zero, they found remnants of a photographic collection kept by the agency. Tens of thousands images were restored from what had been a collection of one million before the attacks.
One photo contact sheet - a picture of the Port Authority's aviation director - was discovered by a recovery worker two days after the attacks. It was given to the Sept. 11 museum, along with office IDs, letters and other bits of paper that were recovered in the rubble in the days and weeks afterward.
Jan Ramirez, the curator of the National September 11 Memorial & Museum, said there was no historical consciousness surrounding the site before it was destroyed.
"It was modern, it was dynamic. It was not in peril. It was not something that needed to be preserved," she said.
"Now we know better."