By Chris Francescani and Edith Honan
NEW YORK, March 12 (Reuters) - Two New York City apartment buildings collapsed on Wednesday in an explosion apparently caused by a gas leak, killing three women, injuring at least 36 people and setting off a search for more victims feared trapped in the rubble, officials said.
The blast, which scattered debris across nearby rooftops, brought down the adjacent five-story buildings, with a total of 15 apartments, at about 9:30 a.m. (1330 GMT) on a largely residential Upper Manhattan block at East 116th Street and Park Avenue.
Clouds of thick smoke billowed from the rubble of the apartment houses that had sat above a ground-level church and a piano store in a largely Latino working-class neighborhood. Officials declined to give a number of people still missing.
Mayor Bill de Blasio, who rushed to the scene in East Harlem, where a cascade of twisted and burnt metal blocked the sidewalk and covered parked cars, said preliminary information showed the explosion was caused by a gas leak.
Officials told a news conference the blast occurred 15 minutes after a resident in an adjacent building called Con Edison to complain of a gas odor.
Edward Foppiano, Con Ed's vice president for gas operations, said while the utility could not say for certain what caused the explosion, it was treating the incident as a gas leak issue. The utility most recently responded to customer complaint about a gas odor in the area in May, but the issue had been resolved, Foppiano said.
The National Transportation Safety Board said it was investigating the "gas explosion and subsequent fire."
Metro-North Railroad, which had shut down train traffic moving through Manhattan while it cleared debris from the tracks, announced in late afternoon it had restored all commuter rail service through the area.
Hundreds of firefighters scoured the mounds of debris for signs of survivors and trapped bodies. Two women were confirmed early in the day as having been killed, and the body of a third woman was found in the rubble later in the day, police said.
One of the victims was identified as Griselde Camacho, a campus public safety officer for Hunter College in East Harlem, according to a message posted on the school's website. Her age was not given.
At least 36 other people were listed as injured, and de Blasio said there were "a number" of people missing.
'THE WHOLE BUILDING SHOOK'
"This is a tragedy because there was no time to warn people ahead of time," de Blasio said. "We are expending every effort to locate each and every loved one."
Most of those injured suffered cuts, broken bones and smoke inhalation, authorities said.
At least three children were among the injured. Two of them were treated for minor injuries and released, while a third was in critical condition, hospital officials told a news conference.
Neighbors said they thought an earthquake was shaking them from their beds and breakfast tables. The explosion, which could be heard from blocks away, shattered windows around the neighborhood.
"I heard a big explosion. Boom!" said Aisha Watts, who lives in the building next door.
"The walls started crumbling down. The windows were gone," Watts said. The mother of three said she feared she would die but was soon rescued by a neighbor who kicked down the jammed door to her home.
Six blocks away, Robert Pauline's apartment was rocked by the explosion.
"All of a sudden the whole building shook. We had no idea what was going on," said the 56-year-old Columbia University data processor.
President Barack Obama was briefed on the collapse and sent his condolences to the victims' families and his support to first responders at the scene.
"Our thoughts and prayers go out to everyone impacted by this incident," the White House said in a statement.
Crowds of residents, their faces covered with protective scarves and masks, filled the sidewalks of surrounding streets, which were blocked off with yellow police tape.
"It's a very active scene. It's a very chaotic scene," said Fire Department spokesman Michael Parrella.
Fire trucks used high cranes to spray blasts of water into the rubble, as dozens of ambulances and police cruisers with flashing lights swarmed the scene.
During the morning commute, trains were held at nearby stations because of debris on the tracks and passengers were ordered off the Metro-North Railroad cars at the Fordham stop in the Bronx, passengers said.