I would think if that happened (that the plane landed safely, somewhere other than its intended destination, with no terrorism), someone would have been contacted by now.
Were they completely out of fuel? Nobody had a cell phone or an air phone they could charge?
They probably crashed. Most likely, the plane is on the bottom of the sea. They just haven’t found it yet, but sooner or later, they probably will.
Granted, the sea doesn’t always yield her secrets. So we may well never know for sure what happened.