The discovery stirred up renewed anger and anguish among families of the dead. "These are the bones that these mothers bore," said Rosaleen Tallon, whose brother died on Sept. 11.
Michael Bloomberg called agencies to the meeting to "put them all together in a room to see what else we should go look at and why this wasn't discovered five years earlier." He also said that the city was planning to scour the site again for remains, examining other manholes and areas that might have been overlooked.
Attending the meeting were Police Commissioner Raymond Kelly, Fire Commissioner Nicholas Scoppetta and several other top city officials, along with forensic anthropologists from the Office of the Medical Examiner.
Chief Medical Examiner Charles Hirsch told The Associated Press he was eager to see what came out of the meeting. "We've been in touch with the families and expressed our concern," he said as he headed inside.
Meanwhile, police and forensic experts dug through a pile of rubble at the site Friday in search of more remains, an official said. The search involved additional material pulled from the manhole where the bones were found this week, and was expected to yield additional remains, said the official, who spoke on condition of anonymity because the official was not instructed not to speak publicly about the matter.
Construction work on several ongoing projects at the site — the Sept. 11 memorial, the 1,776-foot Freedom Tower and a transit hub — continued without interruption Friday, said Port Authority of New York and New Jersey spokesman Steve Coleman.
The remains, some as big as arm or leg bones, were found by a Port Authority contractor working with a Consolidated Edison crew excavating a manhole at street level, Coleman said.
The location where the bones were found is next to where a podium is put up on Sept. 11 anniversaries for families to read the names of their loved ones.
Family members called Friday for an investigation by Congress and state Attorney General Eliot Spitzer into the failure to completely remove the remains from ground zero.
The group WTC Families for Proper Burial also called for ground zero construction to be halted until a proper search for remains can be completed.
Diane Horning, who lost a son on Sept. 11, said at a news conference that a small piece of her son's body, found 4½ years ago, was located near the latest discovery.
"Why were these remains removed and the site compromised? The entire recovery has never been handled as a crime scene," said Horning.
The families said officials rushed to clean the debris from ground zero without properly considering the remains.
Con Edison said that at the direction of the Port Authority, it entered the lower Manhattan site on Wednesday to remove material from two manholes that had been damaged and abandoned after the 2001 collapse of the twin towers.
Crews hauled the excavated materials Wednesday to a work center more than a mile away, as is customary, Con Edison said. No one noticed there were human remains.
On Thursday morning, the Port Authority contractor spotted the remains, and the medical examiner's office was contacted. More remains were found at the Chelsea site where the excavated material was taken, said Con Ed spokesman Mike Clendenin.