Though the devastating deaths of 9/11 happened more than a decade ago, there are still families waiting to hear that their loved ones' remains have been found.
Firefighter Jim Riches pulled out his son's body from the rubble at the World Trade Center, but he still receives calls about the city finding more pieces of his remains.
"They'll call you and they'll tell you, 'we found a shin bone,'" he said. "Or: 'We found an arm bone.' We held them all together and then we put them in the cemetery."
Though it's a dreadful discovery, it is also a hopeful one, as many families have no remains for a proper burial.
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For the first time in three years, investigators are again sifting through the debris, but this time in an area they were not able to get to before
They've already found two potential human remains on Monday.
"We would like to see the other 40 percent of the families who have never recovered anything to at least someday have a piece of their loved one," Riches said. "That they can go to a cemetery and pray."
The debris from the site took 60 truckloads to unload. Investigators are now going to go through the remains for the next 10 weeks.
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Their last effort to discover human remains ended in 2010.
About 2,750 died on 9/11, and 1,634 people have been identified.
"We have been monitoring the World Trade Center site over time and monitoring the construction," Ellen Borakove, a spokeswoman for the medical examiner's office, said. "And if they see any material that could possibly contain human remains, we collect that material."
But there are some human remains that can't be identified, as they were too degraded to match DNA.
As time passes, families become more upset that their loved ones' remains have yet to be found.
"Quite frankly, they should've excavated this and searched it 12 years ago," Diane Horning, whose son died on 9/11, said. "Instead, they built service roads and construction roads and were more worried about the building and the tourism than they were about the human remains."
It has been a difficult battle to identify remains over the years.
In 2005, Charles Hirsch, the city's chief medical examiner, said that they were suspending identification attempts because they had "exhausted limits of DNA technology."
A year later remains were found on a bank tower roof and in a manhole, a discovery which uncovered around 1,500 pieces of remains.
The medical examiner's office hopes that this recent excavation will uncover even more remains, and said they will keep monitoring the site.
Charles G. Wolf, who lost his wife in 9/11, said he is happy they are searching for more remains, but he doesn't expect to find hers as he believes she vaporized.
Though it bothered him at first that he did not have a grave to visit, he said the September 11 memorial has given him a place to mourn, but hasn't given him closure.
"You heal. You carry on," he said, "It's not closure."