BANGKOK, SEPT. 1 -- Rescue workers today recovered the remains of 39 persons who died yesterday when a Thai Airways 737 crashed into the sea as it approached the resort island of Phuket off the western coast of Thailand.

The plane was carrying 74 passengers and nine crew members on a domestic flight from Hat Yai in southern Thailand to Phuket. All 83 persons are believed to have died.

The cause of the crash remains unclear, but Thai Airways spokesmen dropped their earlier claim that the pilot had veered off course to avoid hitting a second aircraft as both planes approached the Phuket airport. The second plane belonged to Dragonair, a Hong Kong-based airline.

Officials at the crash site reported that divers had located the plane's "black box" of monitoring instruments but said they were unable to retrieve it from the sea floor. The plane is submerged in more than 50 feet of water, about four miles off the island.

Officials at the Phuket airport reported today that the Thai flight was scheduled to land four minutes after the Dragonair flight and said the Thai aircraft was flying about 2,000 feet higher than the Dragonair plane moments before the crash.

Phuket Gov. Chalerm Promlert quoted witnesses as saying the Thai plane swayed from side to side before crashing nose-first into the sea. Fishermen reported seeing smoke coming from the front of the plane before it crashed and said the plane burst into flames on impact.

"Every single piece of the plane was smashed," the governor told Reuter. "There is no way there were any survivors."

A team of investigators, including representatives of Thai Airways, several Thai government agencies and the Thai Air Force, began investigating the cause of the crash today.

Rescue workers brought in a crane on a barge and raised one of the plane's doors, its handle still in the closed position, as well as a 20-foot piece of the plane's fusilage, some fragments of its wing flaps and two badly damaged seats.

According to Thai Airways, there were 37 foreigners on the flight, including two Americans.