EE CRESTED PIT 10-RAMP 2 DIVIDE, HEADING SOUTH DOWN-GRADE TO THE COAL PLANT. WHEN FOR NO APPARENT REASON, THE TRUCK VEERED SLIGHTLY TO THE LEFTAT AT THE RAMP JUNCTION. THE TRUCK RAN THRU THE BERM, ABOVE THE OLD PIT 10 READY LINE, WHERE THEOPERATOR WAS EJECTED FROM THE TRUCK