WASHINGTON — Fairfax County officials are trying to figure out why a 17-year-old girl jumped or fell out of a moving car driven by one of her grandparents.

A preliminary investigation shows that Jasmyne Grant, of Reston, exited through the rear of the four-door Infiniti sedan shortly before 2 a.m. on July 31. She landed in the travel lanes of Lee Highway near Interstate 495.

Grant was taken to a local hospital with life-threatening injuries. She died Aug. 13.

The incident is under investigation. Anyone with information is asked to call Crime Solvers at 866-411-TIPS/8477, e-mail at www.fairfaxcrimesolvers.org or text “TIP187” plus your message to CRIMES/274637 or call Fairfax County Police at 703-691-2131.

Follow @WTOP on Twitter.