I’m sure that when witnesses talk about “wings” coming off they are actually referring to the right and left horizontal stabs and maybe the rudder. Only the right wingtip seems to have been severely damaged on the main wing.
If there was a mid-air explosion in the tail area — even one second before touch down — this is a really big deal.
It is unlikely the baggage compartment extends that far back. The 777 has no tail engine with associated fuel lines or even an APU in that location (I don’t think).
So what caused the explosion? I hope it wasn’t a SAM!
Still seems more likely to me the tail damage occurred on hard/premature landing rather than a mid-air explosion.
The rear pressure bulkhead was blown out rearward, causing the tail to blow off, IMHO!!! Something odd occurred inside the passenger fuselage.