Primitive overriding biological reflexes include:
1) Seeking oxygen at all costs, and
2)Moving away instantly and forcefully from intense heat that burns your flesh.
You and I my dearest friends would reflexively also use superhuman strength to break through inches thick plate glass windows to get oxygen and irrestitably move away from 1400 degree Fahrenheit, steel melting jet fuel inferno.
These dear souls, now in heaven, were brutally murdered in a carefully crafted, well planned event that defines the word "holocaust."
"The perfect storm" has a good description of the dilemma the body faces when underwater without supplemental oxygen for an extended period of time. Eventually you open your mouth underwater and try to take a breath. In some people, water going down the windpipe triggers the throat to close tight which results in suffocation. In others the lungs just fill with water and they drown. Either way, the end result is the same.
On the radio, they were discussing the jumpers and one guy said that the sad thing was that they weren't falling from high enough to pass out before they hit.
I have never heard of passing out from falling from any height.