The mystery of the missing Malaysia Airlines flight has focused attention on instances in which planes disappear and wreckage is never found.
One such case got much media attention 50 years ago in Los Angeles.
In April 1964, a DC-4 plane bound for Los Angeles from Wake Island disappeared over the Pacific Ocean.
Nine people, including two children, were aboard and presumed killed.
According to The Times reports at the time, the pilot radioed about engine problems just before the plane lost contact about 500 miles southwest of Los Angeles.
There was an extensive search. At first, officials checked reports of flares being set off and SOS emergency transmissions. But those reports were eventually discounted.
Navy searchers found an oil slick, and there were reports of something that might have been the plane's tail sinking into the ocean.
But stories at the time said the search ended without the plane or its passengers being found.
The plane was owned by Facilities Management Corp., a company based in Hawthorne.