Makassar, Indonesia ? A fisherman found a piece of a Boeing 737 that disappeared more than 10 days ago, the first hard evidence that the plane carrying 102 people had crashed into the sea off northwestern Indonesia, a top search official said today.

The piece of tail from Adam Air Flight KI-574 was recovered Wednesday in the Makassar Strait, 185 miles off Sulawesi Island’s coast, said Eddy Suyanto, the head of search and rescue operations.

Suyanto said the serial number on the yard-long tail stabilizer matched the one given to search teams by Boeing.

No survivors or bodies have been recovered, Suyanto said.

A U.S. Navy oceanographic survey ship arrived Wednesday in an area 125 miles from where the tail piece was found to determine whether separate metal objects found on the seabed there were also wreckage from the plane. The results of the U.S. investigation have not yet been made public.

An Indonesian vessel located three pieces of debris on the Makassar Strait seabed after local fishermen told authorities they had spotted a low-flying, unstable aircraft in the area but lost sight of it after hearing a loud bang.

The USNS Mary Sears, which has sonar and satellite imagery capabilities, was called in to see whether the metal could be the remnants of the plane, which fell off radars in the area during 80 mph winds on New Year’s day, Suyanto said Wednesday.

The debris was roughly 2 1/2 miles from the West Sulawesi provincial capital of Mamuju at a depth of about 4,500 feet, he said.

The pilot of the Adam Air plane, which left Java island for the North Sulawesi provincial capital of Manado on Jan. 1, twice changed course because of rough weather but did not issue a mayday or report technical difficulties, officials said.

With no emergency location signal to guide more than 3,600 soldiers, police and volunteers searching in the island’s dense jungles and surrounding seas, teams have fanned out over a nearly 30,000-square-mile area, almost the size of South Carolina.

After mistakenly claiming last week that the wreckage had been found with 12 survivors, officials were cautious in discussing the discovery of the underwater debris.

It could be a sunken ship or something else, Suyanto told reporters.