A 13-year-old pedestrian suffered serious injuries when she was involved in a collision with a car in Hazelwood, Gossops Green, Crawley.
The incident happened at about 8.45am on Tuesday (March 6) as the teenager crossed the road.
She collided with a black hatchback style car, which drove off after failing to stop.
Anyone who saw the collision, or who has any information about it, is asked to call 101 quoting serial 335 of 6 March.