PHILADELPHIA -- An Amtrak passenger train derailed in Philadelphia, Pennsylvania, on Tuesday night, the National Transportation Safety Board said.
Word of the derailment quickly spread on social media, with posts on Twitter describing crews searching for wreckage and helicopters hovering overhead.
Amtrak said on Twitter that Northeast Regional Train 188 had derailed north of the city but did not provide additional information. The train was traveling from Washington to New York.
Video from CNN affiliates KYW and WPVI showed what appeared to be an overturned train car and people with flashlights searching the area.
About 200 people were on the train when it derailed, WPVI said.
Former Congressman Patrick Murphy said on Twitter that he was aboard the train when it crashed. "Helping others," he said. "Pray for those injured."
Later he shared a photo that showed a firefighter inside the train.
On Instagram, another passenger posted video of what appeared to be a rescue in progress.
Scanner report: Over 50 people injured Philadelphia Amtrak crash now. Philadelphia Fire Department striking 3rd alarm.
— Jim MacMillan (@JimMacMillan) May 13, 2015
We are aware of the derailment of Northeast Regional train 188 north of Philadelphia and will provide updates as they become available.
— Amtrak (@Amtrak) May 13, 2015
NTSB is currently gathering information about tonight's Amtrak derailment in Philadelphia.
— NTSB (@NTSB) May 13, 2015