Malaysia confirmed early on Thursday that a piece of a wing washed up on an Indian Ocean island beach last week was from the Malaysian Airlines jet MH370, the first trace of the plane found since it vanished last year with 239 people on board.
"Today, 515 days since the plane disappeared, it is with a heavy heart that I must tell you that an international team of experts have conclusively confirmed that the aircraft debris found on Reunion Island is indeed from MH370," Prime Minister Najib Razak said in an early morning televised statement.
The announcement, by providing clear evidence that the plane crashed in the ocean, closes one chapter in one of the biggest mysteries in aviation history, but still leaves unanswered questions about precisely why it disappeared.
"Malaysia Airlines would like to sincerely convey our deepest sorrow to the families and friends of the passengers onboard Flight MH370 on the news that the flaperon found on Reunion Island on 29 July was indeed from Flight MH370," the airline said in a statement issued as soon as the prime minister had spoken.
"This is indeed a major breakthrough for us in resolving the disappearance of MH370. We expect and hope that there would be more objects to be found which would be able to help resolve this mystery," it said.
The airline's priority would be to update families and cooperate with authorities "on the investigation and recovery of this tragic accident", it added.
International crash experts had been examining the wing part found on France's Indian Ocean island of Reunion last week.
A statement from a French prosecutor involved in the case said there would be a news conference "on the subject of the disappearance of the Boeing MH370" at 1800 GMT in Paris, where it was still Wednesday evening.
The examination of the part is being carried out under the direction of a judge at an aeronautical test facility run by the French military at Balma, a suburb of the southwestern city of Toulouse, and witnessed by Malaysian officials.
Officials from the United States and manufacturer Boeing were also on hand to advise whether the piece can be tied to Flight MH370, which went missing on March 8 last year while en route from Kuala Lumpur to Beijing. Boeing declined to comment.
The airliner is believed to have crashed in the southern Indian Ocean, about 3,700 km (2,300 miles) from Reunion.
The Balma test centre specialises in metal analysis and is equipped with a scanning electron microscope capable of 100,000 times magnification. It was used to store and analyse debris from an Air France jet which crashed in the Atlantic in 2009.
The Boeing 777 was minutes into its scheduled flight when it disappeared from civil radars. Investigators believe that someone deliberately switched off the aircraft's transponder, diverted it thousands of miles off course, and deliberately crashed into the ocean off Australia.
In January, Malaysia Airlines officially declared the disappearance an accident, clearing the way for the carrier to pay compensation to relatives while the search goes on.
A $90 million hunt along a rugged 60,000 sq km patch of sea floor 1,600 km (1,000 miles) west of the Australian city of Perth has yielded nothing.
The search has being extended to another 60,000 sq km (23,000 sq miles) and Malaysian and Australian authorities say this will cover 95 percent of MH370's flight path.