FAIRFAX, Minn. (AP) _ Four high school girls out for the night after their final day of classes were killed early Saturday in a one-car accident, authorities said.

The Renville County Sheriff's Department and the State Patrol were investigating the accident and did not release many details. Investigators said the girls were thrown from the wreck but they did not know who had been driving.

The victims were identified as Christina Jane Freyholtz, 16; Carrie Ann Clobes, 16; Lori Lea Waibel, 15; and Janis Rae Schroeder, 15.

The girls, all sophomores, had finished their last day of classes at Fairfax High School on Friday. A memorial service will be held Monday at the school, said Marlin Waibel, Lori Lea's father.

He said parents were still uncertain Saturday night exactly what the girls had been doing before the accident.

''They were just driving around,'' he said. ''It's a small town, and there's not much to do but drive around.''

Blood samples were taken for routine alcohol tests, officials said.