The search for Malaysia Airlines Flight MH370 was called off Tuesday after nearly three years combing the desolate Indian Ocean and its deep seabed, leaving one of the greatest aviation mysteries of all time unsolved.

The governments of Malaysia, Australia and China, said crews had finished an underwater sweep of a 46,000-square mile zone of seabed without finding the missing Boeing 777.

The most expensive search in aviation history cost around $150 million but failed to locate the plane, let alone answer the questions about its disappearance in March 2014.

The search was unsuccessful

Despite using cutting-edge technology and advice from highly skilled professionals who are the best in their field, the search has not been able to locate the aircraft.

The jet carrying 239 people on board vanished from civilian radar. Scientists decided the plane had turned south, directing the search towards a vast arc of ocean west of Australia. 

Just last month, officials investigating the plane's disappearance decided they might have been searching in the wrong place.

But the three governments who had bankrolled the search had already concluded that the search would be suspended.

Finally, confirmation came in July 2015 that the plane had crashed in the Indian Ocean, when a wing flap was found on Reunion Island, east of Madagascar. 

By then, the search for the plane itself had long moved underwater, with a lot of ships dragging sonar-equipped "towfish" back and forth through the ocean to map huge areas of deep sea floor to look for signs of wreckage. Unmanned submarines were used to take a closer look at objects of interest. Still, nothing, apart from a couple of old shipwrecks.

And there was a final twist in December when Australia's Transport Safety Bureau declared that another review now suggested they had been looking in the wrong place.

But Australia's government had lost patience with the plane - or run out cash, rejecting the bureau's recommendation.