Witness say the trio had been drinking Friday night at a campground near Washington Fields. They were then seen in a small car driving erratically without headlights in the dark on rugged dirt roads.
The Deseret News reports the mangled wreckage was discovered early Saturday at the bottom of a 300-foot ravine.
The Washington County sheriff's office says the survivor was taken to Dixie Regional Medical Center in St. George with unknown injuries.
Authorities say it could be days before they are able to retrieve the car. The sheriff's office hasn't said if the bodies of the two people killed have been recovered.
Information from: Deseret News
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