With one person still unaccounted for, authorities are searching the rubble for survivors at the scene.
Telescopic cameras and sound devices have been deployed to search small spaces in the wreckage.
Less than 50% of debris has been removed from the site after Wednesday's incident, which injured more than 60.
"We have to think of survivors and work in that way, with hope," Fire Department of New York Chief Edward Kilduff told US media of the ongoing operation.
Bulldozers are removing debris from the scene in the Park Avenue and 116th Street area, with authorities aiming to reach the first floor by Saturday and then on to the basement to search for victims.
On Friday, city officials and utility company Con Edison continued to search for the source of a gas leak believed to have caused the explosion.
In question is whether the city's aging gas and water mains, dating as far back as the 1800s, played a role.
New York City still uses an estimated 3,000 miles (4,800 km) of old cast-iron pipe to deliver gas.
The old infrastructure poses a "fundamental challenge", according to Mayor Bill de Blasio.
Local residents were said to have complained recently about "unbearable" gas smells in the area, raising questions about whether such complaints were ignored.
Con Edison said a resident in a nearby building reported smelling gas shortly before the incident, but a team of engineers did not arrive until it was too late.
Edward Foppiano, a Con Ed spokesman, said there was only one gas odour complaint on record with the utility from either address. It was from last May and involved a small leak, according to the utility.
Rescue operations are continuing two days after a gas leak blast demolished two buildings in East Harlem, New York City, killing eight people.