A truck ran off a rural Colleton County road late Monday night, killing two occupants and seriously injuring a third, authorities said.

Though the wreck on Langdale Drive likely occurred between 10 and 11 p.m. Monday, authorities didn't receive the first 911 call about it until about 5:30 a.m. Tuesday, Colleton County Coroner Richard Harvey said. The occupants, none of whom was wearing a seat belt, were thrown around the inside of the truck's cab.

The coroner identified the driver and a female passenger who were pronounced dead at the scene: 21-year-old Johnathan Cox of Walterboro and 23-year-old Gina Britt of Round O. A third passenger, whose identity was unknown, was flown to Medical University Hospital.

The S.C. Highway Patrol said the 2002 Chevrolet pickup truck in which the three were riding was headed south at the time of the wreck. It went off the right shoulder near McCleod Road, then struck a mailbox and a tree, Lance Cpl. Bob Beres said.

The scene was north of Walterboro, between Interstate 95 and S.C. Highway 15.

Reach Noah Haglund at 937-5550 or nhaglund@postandcourier.com.