This post is being updated as more information becomes available.
Two buildings at 116th street and Park Avenue have collapsed following an explosion, leading to at least two deaths and 18 injuries. At a press conference, New York City Mayor Bill de Blasio said that the explosion was "based on a gas leak." He added that there was no indication of foul play.
According to de Blasio, a neighbor reported a gas leak to Con Edison 15 minutes before the explosion occurred. The FDNY is in the process of putting out the fire, and Con Edison is working on turning off the buildings' gas supplies. Once the fire is put out, there will be a search for missing individuals.
A senior city official told the New York Times that there will likely be more fatalities.
"This is an occupied building, there were people living there, we have people missing,” the official said. “There was a complete collapse; the fire is still going so we can’t make a search. There will be fatalities.”
NBC News has confirmed the second death.
Sidewalks for blocks around were littered with broken glass from shattered storefront and apartment windows. Witnesses say the blast neat Park Avenue and 116th Street was so powerful it knocked groceries off the shelves of nearby stores.
A neighboring building was severely damaged. The cause of the blast was unclear.
Police, some wearing gas masks and medical masks, handed out medical masks to residents and onlookers because of the thick white smoke that shrouded the area.
Eoin Hayes, 26, said the explosion shook his entire apartment building in Harlem at about 9:30 a.m. He ran to the window and saw flames consuming one building and smoke rising into the air.
"I was in my bedroom and the explosion went off, it kind of shook the whole building," Hayes said. "You could feel the vibrations going through the building."
Hayes lives less than 10 blocks from where the explosion happened. He said the fire consumed one building and then moved on to another building adjacent to it, though about 40 minutes later the flames had subsided and there was mostly just smoke. Both buildings appeared to be residential.
"I ran to the window and saw the fire and the smoke going up and the sirens start," Hayes said.
The explosion occurred very close to elevated Metro-North commuter railroad tracks. Metro-North service was suspended to and from Grand Central on all three train lines while employees remove debris from the tracks.
The fire department said it sent nearly 170 members to the scene.
More news and photos are coming in via Twitter:
The Daily Beast has posted this video from the scene: