4096
A few things.
I personally found the prospect of video of survivors in agony distasetful and chose not to view it. This is just how I feel about it. Not quite sure why I am mentioning it frankly but it for sure does not interest me.
-4096 ft per min.
This is about 50mph straight down. One mile per min is 60mph.
The rates of climb/descent quoted on the mode-s/adb web site seem to be expressed as a multiple of 64 ft/min. 4096 is 64 times 64. It may be that -4096 is full scale and indicates that the sensor is stuck on full scale and is not actually a rate of descent. Perhaps after the crash?
I would guess that such a rate of descent (50mph) along with a 100mph horizontal component would have caused more damage than has been observed.
*Additionaly*
The speeds quoted on the mode-s/adb web site are groundspeed AND rate of descent. One thing that occured to me is theat the *airspeed* is the vector sum of those two speeds plus any wind. Not sure if this makes any difference to anything but it seems worth noting.