Three college students exploring a cave got lost but were rescued and declared uninjured Sunday, more than a day after they entered the cavern, authorities.

The two women and one man, found in a 500-foot-long crawl space about the width of a sewer pipe, waited there knowing search teams would arrive, said Lt. Matt Cox of the Austin Fire Department.

"They did everything right," Cox said. "They came out safe and sound, and they're going to school tomorrow."

The University of Texas students emerged from Airman's Cave tired and hungry Sunday night but with no injuries. They had left a trail of leaves during their exploration so crews could find them if they got into trouble, Cox said.

The group went into Airman's Cave on Saturday morning and told friends to call for help if they weren't back by midnight, Cox said.

"They accounted for something like this happening," Cox said.

Jarvis Brown, whose 20-year-old son Jeff was among those in the cave, said his son had been cave exploring before.

"We're very elated, for sure, and thankful that God protected them," said Brown, of San Antonio.

The narrow, 12,000-foot long cave is one of the most difficult for cave explorers in Austin and an easy place to become disoriented, authorities said.

The "keyhole" entrance to the cave, which is in a greenbelt area about five miles south of downtown Austin, is less than 18 inches across. Many places in the cave can be accessed only by crawling, authorities said.

During the search, crews found water bottles and cell phones apparently left behind by the students. Rescuers had left food, water and medical supplies throughout the cave.