Here we go again.... Deja vu from Metrojet thread.
After theories of engine failures, the tail breaking off, loss of cabin pressure, we are now just waiting for the theory about lithium batteries in the hold/ cabin.
I could cut and paste previous posts on Metrojet.
3 probable causes;
1- Terrorism
2- Deliberate actions in the Flight Deck (could be combined with 1 above)
3 -LOC (as per Air Asia)
The wreckage, passenger bodies (RIP) and later, the CVR/ DFDR will confirm one of the above.
As it is an Egyptian carrier, out of Paris, at the border of the FIR, No.1 looks to be the more likely.