DICKINSON, N.D. — Three college softball players found dead after their sport utility vehicle went into a pond on a North Dakota farm during a stargazing trip likely drove straight into the water in the dark, authorities said Wednesday.

Stark County Sheriff Clarence Tuhy said the women's SUV was found resting on its wheels Tuesday in about 10 feet of water hidden by tall grass, with the doors and windows closed.

"When you're not familiar with an area like that it would have been very easy to drive into," Tuhy said.

The sheriff said the Dickinson State University students were on private property. He stopped short of saying they were trespassing.

No foul play is suspected in the deaths of Kyrstin Gemar, 22, of San Diego; Afton Williamson, 20, of Lake Elsinore, Calif.; and Ashley Neufeld, 21, of Brandon, Manitoba. The bodies of the women and Neufeld's dog were found inside the SUV after signals from their last desperate phone calls late Sunday helped lead authorities to the farm.

Police Lt. Rod Banyai said authorities do not expect autopsy results for a week or two. The autopsies will help determine the exact cause of death and whether the women were under the influence of drugs or alcohol. Authorities have said there is no indication they were. The North Dakota Highway Patrol also will examine the 1997 Jeep Cherokee to determine if the vehicle malfunctioned, Banyai said.

The students were believed to be in the Jeep when two of their friends received telephone calls late Sunday before the lines quickly went dead. Police described the first as a "very scratchy" call for help in which one of the students said they were near water.

Tuhy said the calls, which authorities were able to track to cell phone towers, were critical in leading searchers to the vehicle. He said it wasn't clear if emergency crews might have been able to reach the women had they called 911 instead of their friends.

"There could have probably been some location formed out of that (Sunday night) but if it would have been timely enough, I don't know," he said.

University President Richard McCallum said classes were canceled Wednesday and a memorial service was being planned on campus Thursday.

"It is times like this that we realize our sense of humanity and our sense of connection," he said.

Family members of the women planned to visit the site on Wednesday northwest of Dickinson, a city of 16,000 people that is about 100 miles west of Bismarck.

Gemar's father, Lenny, said Tuesday night after a prayer service on campus that "it's the worst day of my life."

Neufeld's mother, Bev Neufeld, said her family was trying to be strong.

"That's what she would want, and we have so much support here (on campus)," she said. "We know how much Ashley loved this school. I would just like everybody to remember Ashley's smile and personality."

The 2,700-student university listed Gemar as a senior business major who played third base on the softball team. Neufeld was a senior outfielder working on a psychology degree, and Williamson, a junior, was a pitcher majoring in psychology with a minor in coaching.

"I'm sure it will be difficult for quite a while. But we know that they'll be there with us. They would want us to play," softball teammate Jessica Huseby of Hamilton, Mont., said after the prayer service. "We just know they're going to be the 10th, 11th and 12th players on the field with us."