UPDATE: For the latest on this story, head here.

An explosion in upper Manhattan on Wednesday morning destroyed two residential buildings, killing at least three people, injuring dozens of others and scattering debris and broken glass along surrounding sidewalks and streets.

The “major explosion” that destroyed the buildings at 9:30 a.m. was caused by a gas leak, New York Mayor Bill de Blasio said in a press conference.

So far, it seems that the only warning came when a gas leak was reported to Con Edison about 15 minutes before the explosion, he said.

“This is a tragedy of the worst kind because there was no indication in time to save people,” de Blasio  said.

Con Edison said it received a call at 9:13 a.m. and dispatched crews about two minutes later, but they arrived only after the explosion.

The two people first reported as killed were both female, according to the New York City Police Department. A third person’s death was confirmed by the New York City Fire Department at 7 p.m.

In addition, dozens of other people were injured. More than 50 people were hurt, the Associated Press reported. There were also dozens of injured people scattering to hospitals around the area. At least 50 people were injured, the Associated Press reported on Wednesday night. Two dozen patients were taken to Mount Sinai and Mount Sinai St. Luke’s; one of them was in critical but stable condition.

An official with the fire department cautioned that these numbers could rise, noting that some people may only seek medical treatment later in the day.

Numerous people are missing, police and fire officials said, but they declined to provide an exact number because it’s unclear how many people were in the building when the explosion occurred. A city official told the New York Times that more than a dozen people could not be reached, but it was unclear how many of those people just couldn’t be contacted.

Anyone looking for information on friends or family should call 311 from inside New York or call 212-639-9675 from outside New York.

A Red Cross center was established at an elementary school (on 115th Street between 3rd and Lexington avenues) for anyone in need of shelter, counseling or information.

The New York City Fire Department dispatched hundreds of firefighters to the scene, joined by scores of other emergency responders:

The two buildings — at 1644 and 1646 Park Avenue in East Harlem — had a combined 15 residential units, officials said. The explosion blew out windows on surrounding cars and buildings, creating a chaotic scene during the morning rush.

President Obama was briefed on the incident this morning, the White House said, and he will be updated again as new information becomes available. Meanwhile, the National Transportation Safety Board said it was sending a team of investigators to Harlem to look into the explosion.

People in the vicinity reported a loud explosion, sharing photos of the smoke and the aftermath:

The Metropolitan Transportation Authority suspended some service in and out of Grand Central Terminal as a result of the explosion. Metro-North service in and out of Manhattan was halted after the explosion, which sent debris onto the elevated Metro-North tracks nearby. Full service was restored just before 5 p.m.

The collapse occurred on Park Avenue and 116th Street in East Harlem:

This post will be updated as more information becomes available.