Partial remains came from two of the three sites of the attacks: the Pentagon and the Shanksville, Pennsylvania crash site
Partial remains from victims of the September 11 attacks in 2001 ended up in a landfill site, according to a Pentagon-commissioned report released on Tuesday that revealed previously undisclosed blunders at the US military's main mortuary.
The remains came from two of the three sites of the September 11 attacks: the Pentagon and Shanksville, Pennsylvania, where of one of the hijacked airliners crashed. The World Trade Centre in New York City, which was levelled in the attacks, was not cited.
The report suggested the remains were essentially treated like medical waste. They were cremated, placed in sealed containers and given to a biomedical waste firm, which incinerated them.
Retired general John Abizaid, briefing Pentagon reporters on the findings of the independent review of practices at the mortuary at Dover air force base in Delaware, said it was unclear how many partial remains of September 11 victims had been disposed of in this manner. "I don't know that there's a way to find out," Abizaid said.
Last year the Dover mortuary was accused of mishandling the remains of war dead, including losing body parts twice and allowing the partial remains of at least 274 troops to be dumped in a Virginia landfill. That policy was abandoned in 2008 and all partial remains are now buried at sea.
Dover, which is under the control of the US air force, is the main entry port for returning war dead from the conflicts in Iraq and Afghanistan.
Although the report said the assumption among top brass at the time was that "nothing remained" after the cremation and incineration, officials later learned some residual material was left behind, the report said. That material was being dumped in a landfill.The report's claims about the remains of the victims appeared to take air force leaders by surprise as well as a group representing victims of the crashed United Airlines flight in Pennsylvania.
"This is impossible to believe," said Lisa Linden, a spokeswoman for Families of Flight 93, who said the remains from the crash were under the control of the Somerset county coroner.
"Our understanding is that no remains were sent to Dover."
Air force chief of staff General Norton Schwartz and air force secretary Michael Donley said they had not been aware of the incidents and were unable to provide more details. Both asked for time to review the findings and tried to emphasize the path ahead, citing steps that would be taken to improve oversight at the Dover mortuary.
"That's really where we need to focus our time, in improving our current operations to make sure this kind of event does not occur again," Donley said.
The report also disclosed other irregularities. In 2006 the mortuary accidentally treated the victims of a navy T-39 Sabreliner jet crash as medical waste, rather than giving them a group burial.
In January, 2008, the air force paid a $25,000 (£15,000) settlement to the widow of a marine whose personal effects were cremated with him. Abizaid acknowledged that investigations into irregularities at Dover had taken place in the past but had not been acted upon, due to a lack of oversight.
"I will readily admit that there were a series of investigations that took place within the mortuary that ... were not properly taken into account. In other words, corrective actions were not taken," he said. "And with a dysfunctional, isolated chain of command, it could not have."
Asked who was responsible for the lack of oversight, Schwartz, who took his position in 2008, said: "You're looking at him. Me. I'm responsible."
So far no one has been fired over the mishaps at Dover mortuary. But Donley left open the possibility of further disciplinary action because of reprisals by local staff against Dover whistle-blowers, whose complaints brought the initial irregularities to light.