Hercules
PtH,
There was a lengthy account of this (or a very similar) event on the web. As I recall the means by which engines were synchronised involved shutting off fuel and that was done engine by engine until they were all out. Thereafter there was no means by which the crew could re-start and they ditched in the sea in darkness. I have a vague idea one or more survived.
A similar event is also mentioned but in this case the pilot disconnected the automatic sync. before all 4 were stopped and all was well.
Hope this helps.
Sandy.