Could it happen again?

Has the same fate befallen MH370 as that of JAL123?

JAL flight lost part of its tail, resulting in sudden decompression and erratic flying patterns, including rapid raising and falling, before it crashed. 

Quote from The Age

"resulted in its flying an aberrant course that involved turning around, heading back over peninsular Malaysia while rising and falling rapidly again, and finally flying out over the Strait of Malacca to an unknown location."