@ bille1319 & dragon man
Thanks, guys! What I've been searching for through, lo, these 800+ posts.
I'll take the leaked climb rates with a grain of salt. But my suspicion is this crew simply inadvertently penetrated the updraft core of a CB and got tossed out of control. Possibly with some airframe damage (not necessarily a full "in-flight breakup") to exacerbate the LOC.
Why and how they got into that situation will have to wait for the CVR, to find out what they could see out the windows (if anything) and what they could see on the scope (if anything). Along with the other details between "A" and "Z" that we don't know yet.