Four friends who disappeared while exploring a cave near Provo (search) were found dead Thursday in a narrow, underwater passageway between its chambers, officials said.

The bodies of the two women and two men, ages 18 to 28, were found inside the passageway, all facing the outer chamber where they entered the cave, said Lt. Dave Bennett of the Utah County sheriff's office search and rescue team.

"We believe they'd already been into the [deeper] cavern and were on their way out when something went wrong," Bennett said.

Autopsies were planned to determine the causes of death.

Police said the men were wearing shorts and sandals, and the women were dressed in shorts, shirts and tennis shoes. Pieces of a flashlight were found in the water, but it wasn't clear if the flashlight belonged to anyone in the group, police said.

The four had gone to the cave with another friend between midnight and 1 a.m. Thursday, said Provo police Lt. Scott Finch. The other man stayed behind and called 911 when the four didn't return, although the time elapsed was unclear, Finch said.

During efforts to find the missing cave explorers, emergency crews pumped oxygen into the cave and used pumps to drain about 6 inches of water from the submerged passageway.

The location of the spring-fed cave, on public land in a hillside above Provo, has been spreading by word of mouth recently, said Brian Lamprey, 29, an area resident who said he went into the cavern about three weeks ago.

"You hear about it, and it's sort of fascinating — almost like a movie type thing, an underwater expedition kind of fascinating," he said outside the cave.

The entrance to the passageway that connects the chambers is a water-filled hole, 90 feet to 100 feet inside the cave, Bennett said.

Lamprey said he dropped into the hole and worked his way through the narrow underwater passage for about 15 feet before popping up in the next chamber. He said someone had placed a guide rope in the passage.

There was two or three feet of breathable air above the water in that next chamber, which could hold about eight people, Lamprey said.

Police said unlit candles were found in the second chamber.

Provo is 45 miles south of Salt Lake City (search). City officials planned to meet Thursday to discuss what to do about the cave.