Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Investigators Unable to Solve Missing Malaysia Flight Mystery by VOA News One of the world's biggest aviation mysteries remains unsolved after investigators said in a report released Monday they do not know what happened to the Malaysia Airlines plane that disappeared four years ago. Kok Soo Chon, head of the MH370 safety investigation team, told reporters in Kuala Lumpur, "The team is unable to determine the real cause for disappearance of MH370."He said investigators would find out what happened to the plane only "if the wreckage is found." Family members of the flight's passengers and crew expressed their frustration with the report, saying there were gaps in the investigations and too many unanswered questions. On March 8, 2014, MH370 disappeared.The Boeing 777 was carrying 239 people on a flight from Kuala Lumpur to Beijing. The governments of Australia, Malaysia and China suspended the official search in January 2017 after scrutinizing about 119,139 square kilometers of the Indian Ocean floor at a cost of more than $150 million. Officials then concluded that the probable crash site was farther north. After pressure from the families of the victims, the former Malaysian government struck a deal with Ocean Infinity, a U.S.-based exploration company, to restart the search in January this year, on the condition it would only be paid if the Boeing 777 or its flight data recorders, the black boxes, were found. The firm stood to make up to $70 million if successful, but did not find any sign of the airliner, despite scouring the seabed with some of the world's most high-tech search equipment. The latest search for the missing jetliner ended in May when Ocean Infinity announced it had called off its three-month effort to find the plane after searching 112,000-square kilometers.