For those standing on the platform, there was no warning.
But inside the train, in the last few moments, some of the passengers could tell something was wrong.
The commuter train was approaching Hoboken Terminal in New Jersey, a crucial commuter hub for the New York City region, during rush hour Thursday morning. And it was going too fast.
The train smashed into the barriers at the end of the tracks, crashing through them and into the platform. It took out support beams holding up the ceiling of the Beaux-Arts terminal, and the roof began to collapse.