DICKINSON, N.D. -- A Clairemont High School graduate and two of her softball teammates believed to have been on a stargazing trip were found dead inside a Jeep after signals from their last desperate phone calls helped lead authorities to a rural farm pond.

The vehicle was found submerged in only about 12 feet of water. The cause of the deaths was not immediately known Tuesday when the bodies were discovered. Investigators were scheduled to hold a news conference Wednesday morning. Autopsies were planned.

Police Lt. Rod Banyai said he believed the women were inside the Jeep when they called for help late Sunday night, but he did not know whether the vehicle was under water when the calls were made.

"At this time, foul play is not suspected," Banyai said Tuesday night. Investigators were working to determine whether the vehicle had any defects or whether alcohol was involved, he said.

The victims were Kyrstin Gemar, 22, of San Diego; Afton Williamson, 20, of Lake Elsinore, Calif.; and Ashley Neufeld, 21, of Brandon, Manitoba.

The Dickinson State University students were believed to be in the white 1997 Jeep Cherokee when two of their friends received telephone calls late Sunday night. But the lines quickly went dead.

Police described the first as a "very scratchy" call for help in which one of the Dickinson State University students said they were near a lake and water.

Banyai said the pond where the women were found was a couple miles off a road on a farm northwest of Dickinson, a city of 16,000 people. It's about 100 miles west of Bismarck and 60 miles east of the Montana state line.

Banyai said "pings" -- signals sent between cell phones and provider towers -- from the women's phone calls helped narrow the search area. Searchers found vehicle tracks leading into the pond Tuesday afternoon.

"After that was located, the plane flew over the top and it could see that there was a white object in the water," Banyai said.

The vehicle was pulled from the pond about two hours later.

Gemar's father, Lenny, had said it was not uncommon for his daughter and her friends to go stargazing on the spur of the moment. Tuesday night, Lenny Gemar was among those who attended a prayer service inside a packed Dickinson State student center ballroom.

"It's the worst day of my life. A parent shouldn't be burying a child. Kyrstin had such a bright future ahead of her," he said.

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)," Bev Neufeld 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 at the prayer service. "We just know they're going to be the 10th, 11th and 12th players on the field with us."