hull break up in air
I write emergency plans for transport disasters and conduct response exercises and analysis, and have worked with transport companies and authorities on terminal events. I am not a pilot or other aircrew.
The chilling images of bodies minus clothing and with limbs intact seems to indicate structural break up in the air at height (as in Lockerbie).
Standard forensic experience is that the decay process in a corpse will create enough gas in internal organs to overcome the normal natural negative buoyancy after about three days, depending mainly on water temperature. This, sadly, appears to be in line with today's discoveries, and the recovery and identification of bodies is a small comfort of importance to victims' families. Spare a thought for the recovery crews in their line of duty.