SSD,
ISTR the aircraft suffered a vertical gust which induced a 'g' load far in excess of the design load for the wing. Hence the outer wing failure, and also the departure of all 4 engines from their pylons - they carried on under power from the fuel they carried and were found some distance ahead of the main wreckage.
The vertical (strictly, 'normal') gust load induced a corresponding design-exceeding deceleration due to the associated induced drag, and this was enough for the fuel in the centre section tank to slosh forward, break the front of the tank, and carry on until it reached the forward pressure bulkhead, just ahead of the flight deck. Thus the flight deck filled with fuel. The wing fuel behaved similarly, which explains the 'white mist' emanating from the whole span in the published pictures.
One hopes the sudden loads and accelerations experienced by all on board were enough to ensure that no one was conscious and aware of any of these elements of the mid-air break-up. Even 50 years on, these are sad to report.
R.I.P.