Crews continued combing through debris in East Harlem on Saturday as investigators searched for clues in the explosion that leveled two buildings Wednesday.
Officials say once the basements are accessible, Con Edison and the National Transportation Safety Board will pressure test the gas lines in order to determine the cause of the explosion.
Fire Commissioner Sal Cassano says crews should be able to reach the underground gas lines and meters Sunday morning.
"We are in the process of removing the debris from the rear of the building, the basement, and we're going to do a quick search down there and try to get as quickly as possible that cleaned up. And then we're going to start moving back towards the front of the building, removing the debris,” Cassano said.
Fire officials said workers cleared roughly 1,500 cubic yards of debris by mid-afternoon Saturday. The debris taken from the buildings is being sent to Randall’s Island for forensic tests.
Underground tests done just hours after the explosion show high levels of natural gas.
Con Ed workers, along with crews from the National Transportation Safety Board, conducted a procedure known as bar testing.
Fifty holes were drilled into the ground around the explosion site and sensors were lowered into them to measure gas levels.
Preliminary tests show there were traces of natural gas in five of the holes and officials with the NTSB say that is unusual.
"Normally, the soil in New York City 18 to 24 inches down into the ground would have zero concentration of natural gas, so the fact that in least five of the holes, the concentration on gas ranged between 5 and 20 percent, that tells us that's a pretty good concentration of natural gas in that area," said Robert Sumwalt of the NTSB. "That further leads to the hypothesis that this may well have been a natural gas leak."
The NTSB says once it's safe it will conduct pressure tests on the gas pipes.
Investigators are asking anyone who was in the area at the time of Wednesday's blast to contact them at firstname.lastname@example.org.
During the debris removal, Cassano said a bible belonging to the Spanish Christian Church, which was destroyed in the collapse, was recovered. The bible was given to the pastor of the church.
“He was overwhelmed. He was certainly overwhelmed with emotion for sure. And you know, it’s a very sacred thing for him. And we hope that we can help them get back to normal,” Cassano said.