The crash happened in Shirley at about 7:45 p.m. on Sunday, Aug. 14, Suffolk County Police said.
The teen was riding her bicycle south on Flintlock Drive at the intersection of Maple Lane when a westbound white, four-door sedan stopped at the intersection and then accelerated, knocking her to the ground, authorities said.
The car left the scene without stopping, police said.
Authorities said the teen was hospitalized for treatment of non-life-threatening injuries.
Suffolk County Crime Stoppers is offering a cash reward for information that leads to an arrest.
Tips can be submitted by calling 1-800-220-TIPS.
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