A Sanpete County woman and a South Dakota woman were both killed in separate accidents Monday on Utah highways.

Ashley Aagard, 21, died in a rollover accident on State Road 132. The Fountain Green woman swerved off the road about 1 p.m. and hit a reflector post, causing her car to roll, said Utah Highway Patrol trooper Cameron Roden.

The vehicle landed on its wheels, but Aagard, who was not wearing a seat belt, was ejected through the car's sun roof, Roden said.

Police are not sure what caused the woman to swerve. Roden said there were no obvious signs of impairment.

• Donna Ruth Sheppler, 67, was killed and a man injured after their minivan crashed Monday afternoon on I-15 near Fillmore.

Sheppler, of Blackhawk, S.D., dozed off momentarily and then overcorrected, rolling her vehicle multiple times around 2 p.m., Roden said.

Sheppler was wearing at seat belt, but was partially ejected out of the driver's window and died at the scene, police said.

Clifford Sheppler, 69, was transported to a nearby hospital with injuries that were not life-threatening, Roden said.