According to authorities, 14-year-old Brittany Vega was crossing the Sunrise Highway in Wantagh at around 6:20 a.m. when she was struck by a 2004 Toyota Camry.
The vehicle was traveling westbound on the highway when the accident happened, police said.
The driver, who was not immediately identified, stayed at the scene and waited for police.
Vega was transported to Nassau University Medical Center where she was later pronounced dead.
No criminal charges are expected in the case.
The fatal accident prompted the closure of the westbound Sunrise for over an hour. Police were still at the scene Wednesday morning investigating the incident.