This is a breaking news story. Check back for updates.

UPDATE Thursday 8 p.m. EDT:  WABC reported that the death toll from the  explosion and two building collapses in East Harlem is now eight people. The news site said that rescue crews are still searching for those who are missing.

  • Seventy others were injured at the scene, at least two of them critically, according to WABC.
  • One of the victims who died was identified as 44-year-old Griselde Camacho, a public safety sergeant at Hunter College. Another victim was identified as 67-year-old Carmen Tanco, who resided on the second floor of one of the buildings. Rosaura Hernandez-Barrios, 21, was also killed. Four bodies found overnight have not yet been identified.

UPDATE 3:23 a.m. EDT: ABC News reported that at least six people have died in the explosion at building in Manhattan's East Harlem neighborhood, and added, citing authorities, that at least 64 people have been admitted to hospital, two of whom have sustained life-threatening injuries, including a 15-year-old boy.

UPDATE 7:43 p.m. EDT: One of the victims was identified as 44-year-old Sgt. Griselde Comacho by Hunter College, according to CBS 2. Camacho served as a public safety officer at Hunter since 2008 and worked in Silberman School of Social Work building, the college said. “We are sad to report that, in an explosion that destroyed two buildings in East Harlem this morning, we have lost a member of the Hunter family….Our hearts go out to Griselde’s family at this terrible time,” Hunter College President Jennifer J. Raab said in a statement. At least 70 people were reportedly injured when an explosion leveled two apartment buildings in East Harlem on Wednesday.

UPDATE 7:20 p.m. EDT: The New York City Mayor's Office has confirmed that three people are dead and nine are still missing as a result of the East Harlem gas explosion.

UPDATE 5:22 p.m. EDT: Metro-North service has been restored, according to the New York Times. Service out of Grand Central had been disrupted by the East Harlem explosion.

UPDATE 5:10 p.m. EDT: ABC News is now reporting at least people 64 injured in the East Harlem explosion.

UPDATE 4:10 p.m. EDT: The injury toll has climbed to at least 55 people, ABC News reported, citing authorities. Among the injured are two FBI agents who were in the area on unrelated business, according to the bureau. An FBI spokesman said the agents had non-life-threatening injuries.

UPDATE 2:24 p.m. EDT: The FDNY is now reporting 22 injuries in the East Harlem explosion. Two of the injuries are considered life-threatening, five are serious/non-life-threatening and 15 are minor injuries.

UPDATE 12:46 p.m. EDT: One of the collapsed buildings contained six apartment units and the second had nine units, according to New York City Acting Buildings Commissioner Thomas Fariello.

UPDATE 12:35 p.m. EDT: New York City Fire Commissioner Sal Cassano said the report of a gas leak came from a building adjacent to the two structures that collapsed.

UPDATE 12:24 p.m. EDT: New York City Mayor Bill de Blasio said the explosion that destroyed the two buildings was "based on a gas leak."

"There was no warning in advance," the mayor told a news conference. "But from what we know, the only inidication of danger came about 15 minutes earlier [before the 9:30 a.m. explosion] when a gas leak was reported to Con Edison."

De Blasio said a team from Con Ed was en route but that the buildings exploded before the team could arrive. He said the fire department arrived within two minutes of a call for help. 

"This is a tragedy of the worst kind because there was no indication in time to save people," the mayor said. He confirmed that there were at least 18 people injured in the explosion. De Blasio did not get into the severity of the injuries.

The fire has still not put out. Once it is extinguished, there will be searches of the rubble. De Blasio said there are "a number of missing individuals."

UPDATE 11:57 a.m. EDT: Multiple media outlets are confirming a second death in the Harlem building explosion. Both of the dead were women.

UPDATE 11:47 a.m. EDT: One of the two buildings that collapsed has been identified as housing the Spanish Christian Church and six apartment units, according to the Village Voice. The other building contained the piano store Absolute Piano. 

The FDNY is holding a media briefing on the explosion at noon.

UPDATE 11:32 a.m. EDT: The FDNY is confirming 16 injured in the Harlem building explosion.

UPDATE 11:21 a.m. EDT: The Wall Street Journal is now reporting at least 17 injuries in the building collapse.

UPDATE 11:07 a.m. EDT: The buildings that exploded were both five stories tall and they both had collapsed down to the first floor, according to a senior FDNY official who spoke to NBC News reporter Tom Winter.

UPDATE 11:03 a.m. EDT: Local utility Con Edison was called about a possible gas leak shortly before the explosion, according to CNN. There is still no known cause of the explosion.

UPDATE 10:57 a.m. EDT: The FBI is at the scene of the East Harlem explosion as a precaution. There are no indications that terrorism was the cause of the incident or that criminal activity played a role, according to ABC News. 

UPDATE 10:49 a.m. EDT: One person has died in the New York City building explosion, according to the Breaking News Twitter account.

UPDATE 10:41 a.m. EDT: The FDNY tweeted that it is transmitting a fifth alarm for the East Harlem fire. The department said there was a "multiple dwelling and explosion collapse."

UPDATE 10:36 a.m. EDT: The Wall Street Journal, citing fire officials, is reporting 15 injuries from the New York City explosion. 

UPDATE 10:25 a.m. EDT: The FDNY has transmitted a fourth alarm for the fire at 116th Street and Park Avenue.

UPDATE 10:22 a.m. EDT: There are now 11 people with injuries from the New York City building explosion, according to PzFeed.

UPDATE 10:14 a.m. EDT: At least four people have been transferred to the hospital with injuries relating to the building explosion and collapse in East Harlem, according to NBC New York.

Original story:

Authorities are responding to the scene of a reported building collapse and explosion Wednesday morning in New York City. The fire department is investigating the incident as a possible three-alarm fire.

The building is at 116th Street and Park Avenue in the East Harlem section of Manhattan, according to NBC New York. That area is near Metro-North train tracks. Metro-North has suspended service out of Grand Central Station because of the incident.

There were reports of people trapped in the building, which was described as residential. The number and extent of any injuries is unknown.

Breaking news Twitter account PzFeed tweeted the following photo of the apparent explosion: