Having seen and overflying the accident site two days after it happened and having 4 engined aircraft experience of similar kind......
A few questions :
If there had been some problem with ONE engine, the aircraft should be able to fly on the remaining engines...
Even with two out, same, although depending on weight....
Why would all four stop, and what about a relight in flight ?
The tower reported the crew called at 45 nm at FL 170, ......the crash site is at 39 nm from Heglig...... 6 nm from that altitude ?
The wreckage is strewn over maybe 100 meters, if forward speed of about 100-130 kts should be maintained, this seems a short distance......
My symphathy with the Family members.