A Martinez woman was killed early Saturday in a crash on Interstate 20 near Grovetown.
Alaina Kensinger, 28, was pronounced dead at Georgia Regents University Medical Center at 9:11 a.m., said Columbia County Deputy Coroner Harriett Garrison.
Kensinger was a passenger in a 2008 Nissan Sentra driven by Christopher Sanmiguel, 27, of Evans, said Columbia County Sheriff's Office Capt. Steve Morris.
Sanmiguel was driving east on I-20 near the weigh station at about 4:30 a.m. when he is believed to have fallen asleep at the wheel, Morris said. The vehicle drifted off the right side of the road, turned sideways and slid approximately 320 feet across the grass before striking a guard rail, he said.
After mounting the guard rail, the car continued to slide until it struck a metal sign pole, Morris said.
Kensinger was taken to the hospital where she later died, while Sanmiguel was treated for non-life-threatening injuries, Garrison said.
Witnesses described Sanmiguel's vehicle as traveling at high speed prior to the crash, Garrison said, adding that both he and Kensinger were wearing seat belts.
Kensinger's body was taken to the GBI Crime Lab in Augusta for autopsy, Garrison said.
Blood-alcohol test results for Sanmiguel are pending, Morris said.