Fifteen people escaped with minor injuries while four more were transported to a hospital with potentially serious injuries, officials said. The incident, at 10:24 a.m. (1424 GMT), involved six cars in an eight-car Manhattan-bound 'F' line subway, they said.
The cause of the derailment was not immediately known but MTA Chairman Thomas Prendergast said the mass-transit agency will begin a full inspection of signals and tracks. NY1 television broadcast video of fire officials evacuating throngs of people in darkness, some through subway grates.
"I saw everyone jerk forward. My car went dark," said Connie Wang, 24, a freelance photographer who was riding in a car in the middle of the train. "There were sparks flying." Wang, who was traveling from her home in Queens to a job in lower Manhattan, said her fellow passengers mostly waited in silence during the hour it took before they were evacuated.