Passengers from an airliner that disintegrated in the air over South America all had their clothes ripped off by by force of imact with the atmosphere...they fell in the jungle far below, salvage crews picked their naked bodies out of the trees...heads and limbs had been torn off along with their clothes.
They were travelling only 500 mph when catastrophic breakup happened...imagine 12,000 mph.
The air is much thinner up at 400,000 feet where they broke up, but they were moving plenty fast all the way to the ground.
I ask God Almighty to bless and cradle them all...a futile request, for I know it's already done...I just need to say it, I guess...(
I believe that with the G-forces involved and the extremely low presure at that altitude, it's very likely that they died instantly. If not instantly, it was very, very brief.