In the 048 seconds Liveleak video post above - at the 004 seconds time point - there appears to be a very clear and bright flash to the right hand side of what appears to be the fuselage ... with the plane going nose down.
It is not possible to see if we are looking at the top or bottom of the plane. So hard to say if its the right or left engine.
Could that be a fire from either an engine separation or from a damaged wing? Or both in tandem?
If you mean the LL video in post #585 its a Strobe and is not the Crash in Rostov-on-Don, its from 2013.