A motorist was killed on the R102 between Fort Jackson and Berlin just after 9 pm on Friday night.
The spokesperson for Provincial Traffic Charles Bramwell says the motorist lost control before rolling down an embankment.
His two passengers were seriously injured.
Bramwell says one of the passengers managed to crawl to the main road and was finally spotted by someone at half-past four on Saturday morning.
Police are investigating a case of culpable homicide.