A piece of a wing that washed up on an Indian Ocean island last week was part of the wreckage of Malaysian Airlines flight MH370, Malaysia said on Thursday, confirming the discovery of the first trace of the plane since it vanished last year.
"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 televised address.
The plane disappeared on flight from Kuala Lumpur to Beijing with 239 passengers and crew on board.
The first piece of direct evidence that it crashed in the ocean closes a chapter in one of the biggest mysteries in aviation history.
But exactly what happened remains unknown and the announcement did not appear to represent any kind of resolution for the families of those on board, most of whom were Chinese.
The airline described the find as "a major breakthrough".
"We expect and hope that there would be more objects to be found which would be able to help resolve this mystery," it said in a statement.
The fragment of wing known as a flaperon was flown to mainland France after being found last week covered in barnacles on a beach on the French island of Reunion.
Despite the Malaysian confirmation, prosecutors in France stopped short of declaring they were certain, saying only that there was a "very strong presumption".
Paris Prosecutor Serge Mackowiak said this was based on technical data supplied by both the manufacturer and airline but gave no indication that experts had discovered a serial number or unique markings that would put the link beyond doubt.
Representatives of manufacturer Boeing confirmed that the flaperon came from a 777 jet, he said, and Malaysia Airlines provided documentation of the missing aircraft.
Mackowiak told reporters in Paris more analysis would be carried out on Thursday, and a fragment of luggage also found in Reunion would be examined by French police.
A group of families from China said French investigators and Boeing must also say definitively the wing piece was from the plane.
"We are not living in denial … but we owe it to our loved ones not to declare them lost without 100 percent certainty!" the families said on their microblog.
Families in Malaysia and Australia expressed similar sentiments.
"They still need to find the whole plane and our spouses as well. We still want them back," said Jacquita Gonzales, whose husband, Patrick Gomes, was a flight attendant on the aircraft.
China\’s foreign ministry urged Malaysia to keep investigating and to "earnestly safeguard the legitimate rights and interests" of the relatives.
Investigators looking at the wing flap are likely to start by putting thin slices of metal under a high-powered microscope, to see clues in the metal\’s crystal structure about how it deformed on impact, said Hans Weber, president of TECOP International, Inc., an aerospace technology consulting firm.
Investigators would probably then clean it and "do a full physical examination, using ultrasonic analysis before they open it up to see if there\’s any internal damage", Weber said. "That might take quite a while. A month or months."
John Goglia, a former board member of the U.S. National Transportation Safety Board, told Reuters much could be learned from examining the metal and how the brackets that held the flaperon in place had broken.
"From that they can tell the direction and attitude of the airplane when it hit," he said.
However, other experts cautioned that the cause of the disaster may remain beyond the reach of investigators until other debris or data and cockpit voice recorders are recovered.
Greg Waldron, Asia managing editor at industry publication Flightglobal, said the amount of time that has elapsed and the dearth of debris made it harder.
"The real key to finding out what, exactly, happened to MH370 is finding the debris field in the seas west of Australia … Debris such as the flaperon can only increase our understanding of the last seconds of the flight," he said.
Officials from Malaysia, the United States, Australia, China, Britain, Singapore, and manufacturer Boeing are on hand for the examination at an aeronautical test facility in the French city of Toulouse.
Flight MH370 disappeared on March 8, 2014, and is believed to have crashed in the Indian Ocean, about 3,700 km (2,300 miles) east of Reunion.
Investigators believe that someone may have deliberately switched off the aircraft\’s transponder, diverted it off course and deliberately crashed into the sea.
An initial search of a 60,000 sq km (23,000 sq miles) patch of sea floor has been extended to another 60,000 sq km.