The US authorities have begun an investigation into the causes of Sunday's train crash in the Bronx area of New York in which four people were killed and more than 60 injured.
The 05:54 from Poughkeepsie to Grand Central Station derailed as it went into a bend in the railway line near Spuyten Duyvil station.
Reports say it was travelling faster than the speed limit in the area.
The train's event recorder, similar to a flight recorder, has been recovered.
The National Transportation Safety Board (NTSB) sent investigators to the site with instructions to inspect the overturned cars and interpret information from the recorder.