A search is on for the wreckage of a plane that crashed into the waters off Jamaica.
Laurence and Jane Glazer's aircraft reportedly went down after they became incapacitated while flying.
Their plane had taken off at 8.45am on Friday from Greater Rochester International Airport in New York en route to Naples, Florida.
The plane's pilot had indicated there was a problem and twice asked to descend to a lower altitude before permission was granted by an air traffic controller.
Radio contact was lost not long after.
US fighter pilots were launched to shadow the unresponsive aircraft, and it was reported the pilot was seen slumped over and the windows were frosting up, which indicated a loss of oxygen.
According to Sky News, the jets were forced to break away, and the plane continued south from Florida over Cuban airspace for another four hours, before crashing into the sea.
The Daily Telegraph reports that military personnel were trying to recover debris spotted 24 miles off the coastal town of Port Antonio, and it was too early to tell if it was the plane wreckage.
Laurence Glazer was a prominent real estate developer from Rochester, upstate New York, and his wife Jane an entrepreneur.
Their son Rick Glazer said that his parents were both licensed pilots, and said he could not confirm they were killed, adding that "we know so little."
However, a number of prominent officials have offered their condolences.
Rochester governor Andrew Cuomo said: "The Glazers were innovative and generous people who were committed to revitalising downtown Rochester and making the city they loved a better place for all."
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