A Vernal brother and sister died in a one-car accident Tuesday morning about one mile west of Duchesne.

Killed in the accident are:Clint Sadler, 18, and Shelley Sadler, no age given.

The Utah Highway Patrol said the two died at the scene of the 7 a.m. accident.

Clint Sadler was driving the car eastbound on U.S. 40 about 60 mph when he crossed the center line and drove into an embankment, UHP investigators said.

Sadler may have fallen asleep and then awakened and tried to stop. Authorities said there were skid marks on the highway.

UHP said they weren't wearing seat belts., a UHP spokeswoman said.