Police identified the girl as Jessica Marleny Ajtzac Guarcas, 18, of Queens.
It happened Tuesday just before 6:40 a.m. at the 74th St. and Roosevelt Ave. Station in Jackson Heights.
According to police, the girl fell onto the southbound E train tracks as the train was heading into the station. EMS responded and pronounced her dead on the scene. Police say the girl was traveling by herself.
Police initially said the victim was 10 years old but later corrected the age, saying she was "likely 18 or 19 years old."
Police said no criminality was involved.
The ID of the victim is pending family notification.