NYFD officials said three of the people who died were thrown from the train. The fourth fatality was found inside the train. The train derailed as it was entering the Spuyten Duyvil Station, so passengers were likely standing when the train derailed, officials said. The NYPD sent divers into the river to search for bodies, but no additional victims were found.
The Metropolitan Transportation Authority (MTA) Police Department has identified the four passengers who died as 54-year-old Donna L. Smith of Newburgh, N.Y., 58-year-old James G. Lovell of Cold Spring, N.Y., 59-year-old James M. Ferrari of Montrose, N.Y., and 35-year-old Ahn Kisook from Queens, N.Y.
Officials confirmed to ABC News 11 people were critically injured, while six people had serious injuries and 46 had minor injuries.
The train was traveling from Poughkeepsie to Grand Central Station when it derailed in the Bronx section of the city around 7:20 a.m.
Between four to five of the train's seven cars derailed. No cars were in the water, despite initial reports, though one car did stop just feet from the Harlem River. Federal investigators say the cars from the derailed train will be turned upright to check for any other possible victims.
A state official told ABC News there is no indication of criminal conduct or terrorism. The National Transportation Safety Board is sending a team to investigate the derailment.
ABC News contributed to this report.