The incident occurred about 6:30 a.m. as the northbound train was moving at a reported 125 mph. A photo from the scene showed the drawbar between two cars disconnected, with only air hoses connected between the cars.
There were 52 passengers aboard the train, according to Amtrak, which is investigating the incident. There were no reported injuries.
A relief train picked up the Acela passengers and transported them to Philadelphia, to meet connections to New York.
“We are currently investigating the cause of the car separation, inspecting every Acela trainset, and taking any necessary actions to prevent a reoccurrence,” said Amtrak spokesman Jason Abrams.
It is the latest in a recent string of mishaps for Amtrak. On Feb. 4, two crewmen died after the southbound Silver Star slammed into an idle CSX freight train in South Carolina. Last week, a chartered train carrying members of Congress struck a garbage truck at a grade crossing in Virginia, killing a man inside the truck.