A 2-year-old boy was fatally hit by a subway train in Lower Manhattan on Wednesday after he became separated from his mother at one of New York City’s busiest stations during the evening commute, officials said.

The boy and his mother were at the Fulton Street station at around 5:30 p.m. when he somehow slipped away from her and into the path of a northbound No. 2 train, the police said. The Fire Department also responded to the station for a report of a patient “pinned by a train,” officials said.

The boy was taken to NewYork-Presbyterian Lower Manhattan Hospital in critical condition, fire officials said. He was subsequently pronounced dead, the police said.

Andy Byford, the president of the New York City Transit Authority, said in a statement that the boy “apparently became separated from his mother” before being hit by the train and that “the circumstances surrounding the incident remain under investigation.”