Bexar County Sheriff's deputies said one man was killed in an accident on Bulverde Road early Friday morning.
The accident happened just after 4 a.m. in the 25000 block of Bulverde Road.
The driver apparently lost control of his Chevy pickup truck and it flipped over several times before landing in the grass.
The driver was thrown from the car. He was to be airlifted to University Hospital, but died before the chopper arrived.
A passenger in the car walked away from the accident with just some bumps and scrapes on the head.
Bexar County spokesman, Louis Antu, said speed played a factor in the crash.
Investigators are waiting on toxicology reports to determine if alcohol was involved in the crash.
The driver has been identified as 20-year-old Connor Neckar of Bulverde.