CHILOQUIN, Ore. -

Oregon State Police say driver fatigue is a suspected factor in a rollover crash of an SUV on Highway 97 that killed a 15-year-old Prosser, Wash., girl early Saturday morning.

Six other people in the Jeep Cherokee were treated for minor injuries, according to troopers.

Around 5:45 a.m., the Jeep driven by Olga Rivera-Chavez, 44, of Sunnyside, Wash., was heading south when it drifted off the southbound shoulder and the driver lost control, troopers said.

The SUV returned to the highway and rolled several times, throwing the teen, who was riding in the front passenger seat and was pronounced dead at the scene. She was identified Sunday, after family notification, as Yasmin Esmeralda Rivera.

Investigators at the scene said they determined she was not wearing a seat belt.  

Rivera-Chavez, Aimme Maldonado, 30, also of Sunnyside, Wash., and a 3-year-old boy from Sunnyside were treated for minor injuries at the scene.
 
Ruth Palomares, 17, a 2-month-old girl  and a 1-year-old boy, all from Yakima, Wash., were taken by ambulance to Sky Lakes Medical Center in Klamath Falls for treatment of minor injuries.  

Troopers said all of the other people in the SUV were wearing seat belts or in child safety seats.

OSP was assisted at the scene by the Chiloquin Fire Department, Chiloquin Ambulance and Oregon Department of Transportation. Highway 97 was reduced to a single northbound lane for about six hours while investigators were at the scene.