Sentence:  Some of the roughly 150 passengers on the early morning Metro - North train from Poughkeepsie to Manhattan were jolted from sleep around 7 : 20 a . m . to screams and the frightening sensation of their compartment rolling over on a bend in the Bronx where the Hudson and Harlem rivers meet .
Span:  compartment rolling over on a bend in the
Question: What exactly made the train flip? Was this a particularly fast turn?