Kara L. Thompson, 17, was found unresponsive in her cell and taken to Southeast Georgia Health Systems Brunswick hospital, where she died about 3:45 a.m., Sheriff Wayne V. Bennett said.
There is no evidence of foul play, and the cause of death is unknown, Sheriff Bennett said.
Ms. Thompson had been in jail since May 8 on a charge of entering an auto, he said. Under Georgia law, the charge results when someone is suspected of going into a vehicle with the intent of committing a burglary or other felony.
Chief Magistrate Tim Barton issued the felony warrant based on a complaint by Peggy Cox, Thompsons grandmother, court records show. The judge set Ms. Thompsons bail at $2,500.
Sheriff Bennett said he has asked the Georgia Bureau of Investigation to investigate the death.
The body was taken to a Georgia Bureau of Investigation crime lab for an autopsy, Glynn County Coroner Jimmy Durden said.
We may not know anything for a few days, he said.