NEW YORK - US experts on Monday were probing how and why a New York City commuter train derailed over the holiday weekend, killing four passengers, injuring more than 60 others, and nearly plunging into a freezing river.
The train may have been speeding when it veered off the rails in the Bronx borough at around 7:20 am (1220 GMT) Sunday as it headed south to Grand Central Station in Manhattan.
The New York Fire Department said four people were killed, 11 others seriously hurt, and another 56 suffered minor inuries.
Some passengers were "impaled" by debris as train cars flew into the air, officials said, while others had to be cut free from tangled metal.
"People were screaming," Joel Zaritsky told The New York Times. "I found myself thrown to the other side of the train."
Many survivors had broken limbs or injuries to their heads or necks. Some were led away with bloodied faces.
"As the cars skidded along the dirt, the windows broke out, the doors opened and they were picking up stones, rock, dirt, tree limbs were flying through the cars," New York Governor Andrew Cuomo described Monday on broadcaster CNN.
Investigators combed the scene and announced that a "multi-disciplinary team" would probe everything from the condition of the tracks to the signaling systems and the brakes.
"Our mission is to understand not just what happened, but why it happened, with the intent of preventing it from happening again," Earl Weener, a National Transportation Safety Board official, told reporters Sunday.
Cuomo said the sharp curve where the train derailed could not be blamed entirely for the accident. "The turn has been here for decades. Trains negotiate the turn all day long," Cuomo said, adding that the train's two "black boxes" - one from the front of the train, the other from the back - had both been recovered.