LEVITTOWN - Police are searching for the driver who killed a 13-year-old girl in a hit-and-run crash in Levittown early Sunday morning.

Detectives say Bryanna Soplin was crossing Hempstead Turnpike at Gardiners Avenue when she was struck by a vehicle traveling eastbound on the Hempstead Turnpike. She was taken to Nassau University Medical Center with trauma to her head and body.

She was pronounced dead by hospital staff at 4:30 a.m.

The driver was last seen traveling eastbound on Hempstead Turnpike, then northbound on the Seaford-Oyster Bay Expressway. The vehicle is described as a 2011 to 2013 blue Town and Country minivan.

Soplin's family says Bryanna, who has Down syndrome, woke up and wandered away from her home in an effort to visit her grandparents, who live more than four miles away in Hicksville. They say she's never done this before.

Her mother, Jennifer Curuchaga, called police after realizing that she had gone missing. Curuchaga pleaded for the driver responsible to turn themselves in to authorities.

She says a witness saw her daughter waiting for the light to turn red before she tried to cross. Curuchaga also believes police have a good picture of the driver's car, due to the fact that there are many cameras at the intersection, including red light cameras.

Anyone with information about the incident is urged to call Crime Stoppers at 1-800-244-TIPS.