Forensic divers probed an underwater cavern Saturday on the northern tip of Aruba (search) for a missing Alabama teenager, but turned up no sign of the young woman.
Later, the team from Florida State University planned to search a lagoon using remote controlled sensors. They planned to check other sites suggested by local authorities over the next two days, said Dale Nute, a forensic scientist who was helping to coordinate the effort.
"If we find something we will call the police and bring it out to them," Nute said.
The search of the cavern and lagoon comes as a Texas-based group that has also searched for Natalee Holloway (search) prepared to abandon its effort within days unless they found some sign of the teenager.
Holloway, 18, vanished in the early hours of May 30, hours before she was to catch a flight home after a five-day vacation celebrating her high school graduation with 124 classmates.
Joran van der Sloot (search), a 17-year-old who was with Holloway the last night she was seen in public, has been detained in connection with her disappearance.
Numerous searches by Dutch marines, Aruban investigators and volunteer rescue groups have failed to turn up any trace of the honors student.
Texas EquuSearch, a Dickenson, Texas-based volunteer group that has searched for more than two weeks, said two Navy SEAL divers were scheduled to come to the island to help look for the teen.
Tim Miller, director of Texas EquuSearch, said the group planned to halt their effort on Tuesday unless they found something.
Miller said prospects for success were slim and said he was convinced the girl was not on the island.
The Florida State divers, who arrived Friday evening, are instructors at the university's underwater crime scene investigation department in Panama City, Fla. They also planned to leave Aruba on Tuesday.