The bodies of all eight people reported missing after a gas explosion destroyed two New York apartment buildings have been recovered, but workers are treating the scene as a rescue operation in case there are survivors in the rubble.
Fire commissioner Salvatore Cassano said no one else is known to be unaccounted for but workers will continue to scour the debris from the flattened buildings for victims.
More than 60 people were injured by Wednesday morning's explosion, and more than 100 others were displaced.
Mr Cassano said about 70% of the debris had been cleared at the blast site in East Harlem, Manhattan, but the pace is expected to quicken after firefighters removed a hazardous rear wall.
He predicted detectives and fire marshals would soon gain access to the buildings' basements to begin the investigation into what caused the explosion.
"Right now we are in the process of removing the final amount of debris," Mr Cassano said. "We should be moving much more quickly now."
The rescue effort continued as federal investigators announced that gas was detected in underground tests of the site in the hours after the explosion, lending support to the hypothesis a gas leak might have been the cause.
National Transportation Safety Board team member Robert Sumwalt said utility Consolidated Edison dug dozens of holes up to 24in deep around the blast site and measured gas levels in them soon after the explosion. Gas concentration was up to 20% in at least five spots, and normal levels in the city's soil should be zero, he said.
"Somehow or another, natural gas did work its way into the ground," he said, adding that pressure testing of nearby pipes was beginning to look for potential leaks.
The NTSB, which investigates pipeline accidents, will conduct an inquiry after police and fire officials locate what might have sparked the blast.
Police have identified six of the dead: Griselde Camacho, 45, a Hunter College security officer; Carmen Tanco, 67, a dental hygienist who took part in church-sponsored medical missions to Africa and the Caribbean; Andreas Panagopoulos, 43, a musician; Rosaura Hernandez, 22, a restaurant cook from Mexico; George Ameado, 44, a handyman who lived in one of the buildings that collapsed; and Alexis Salas, 22, a restaurant worker.
Mexican officials said another Mexican woman, Rosaura Barrios Vazquez, 43, was among those killed.
The eighth body, of a woman whose name has not been released, was pulled from the rubble on Thursday.
Mayor Bill de Blasio, who toured a Red Cross shelter where residents of the destroyed buildings are staying, said the city would find temporary or long-term housing for about 50 displaced families.
"It's our obligation as the city of New York, and I know all New Yorkers feel this way, to stand by them," he said.
Investigators are trying to determine whether the gas leak had anything to do with the city's ageing gas and water mains, some of which were installed in the 1800s. Mr Cassano said they will look at meters, see if there were any breaks in the piping and identify any possible ignition sources, such as light switches.
On Thursday, Mr Sumwalt said the gas main and distribution pipe under the street had been examined in a crater and were found to be intact, with no obvious punctures or ruptures. They had not been torn from the ground.
However, he said, NTSB investigators had been unable to conduct a fuller examination because of the rescue effort, and it was unclear whether the leak came from inside or outside the buildings.