[
link to rt.com]
according to this article
the plane landed nose firstthen the wing exploded into a fireball
so the explosion didn't happen til
after touchdown
it also made 3 attempts at landing,
by-passed the first 2 times, waved off
and went around for another pass
so there were malfunctions somewhere
probably hydraulics related if the
nose gear didn't come down
I would say mechanical or maintenance related
at this point
go-arounds are usually common when landing gear
are not properly extended and locked
or could be sabotage on the plane