On the evening of February 3, 2015, a commuter train on Metro-North Railroad's Harlem Line struck a passenger car at a grade crossing near Valhalla, New York, United States, between the Valhalla and Mount Pleasant stations, killing six people and injuring 15 others, seven very seriously. The crash is the deadliest in Metro-North's history, and at the time the deadliest rail accident in the United States since the June 2009 Washington Metro train collision, which killed nine passengers and injured 80.The crash occurred after traffic on the adjacent Taconic State Parkway had been detoured onto local roads following a car accident that closed the road in one direction. At the grade crossing, a sport utility vehicle (SUV) driven by Ellen Brody of nearby Edgemont was caught between the crossing gates when they descended onto the rear of her car as the train approached from the south. Instead of backing into the space another driver had created for her, she went forward onto the tracks. Brody died when her vehicle was struck by the train; as her vehicle was pushed along the tracks it loosened more than 450 feet (140 m) of third rail, which broke into sections and went through the exterior of the first car, killing five passengers and starting a fire.
Investigators from the National Transportation Safety Board (NTSB) focused on two issues in the accident: how the passengers were killed, since that rarely occurs in grade crossing collisions; and why Brody went forward into the train's path. After an unusually long delay for such investigations that it declined to explain, the board's 2017 final report found the driver of the SUV to be the cause of the accident. It found no defects with the vehicle, the crossing signage and associated traffic signal preemption, or the train engineer's performance. It found that the failure of the third rail to break into smaller segments contributed to the fatalities on the train; while the report ruled out proposed explanations for Brody's behavior such as the placement of her car's gear shift lever, it could not offer any of its own. Despite the report's findings, lawsuits against the town of Mount Pleasant, which maintains the road along which the grade crossing is located, Westchester County, the railroad and the engineer are proceeding.