Metro Nashville police are investigating after a 17-year-old girl was fatally shot on Thursday night.

Detectives are looking for the person or people responsible in the slaying of Ashanti Posey, who they say was a Hillsboro High School senior.

According to police, someone opened fire on her silver Malibu at the intersection of Green Lane and Whites Creek Pike at 10:10 p.m. after she and a friend made a small marijuana sale.

Police say it's unclear whether the shots came from a vehicle or from individuals on foot.

Posey’s friend, who was uninjured, climbed into Posey’s lap and drove several miles on Whites Creek Pike, police said. She then ran to a home and asked for help.

Posey was rushed to Vanderbilt University Medical Center where she died.

Anyone with information is asked to call police at 615-742-7463.

This is a developing story.

Reach Natalie Neysa Alund at nalund@tennessean.com and follow her on Twitter @nataliealund.