It is mostly hydrogen, so most of the energy was dissipated in the first few seconds. Most of the other materials or do not burn well or have very low thermal capacity. It was not on its highest altitude when burning started and drag dumped the falling to much slower speeds than a free-falling person.
I'd estimate that most people who died were trapped or unable to move. Those who were free to run and had enough "air" were very likely to survive.
Hydrogen does not burn energetically, especially before it has been mixed with oxygen. The tragedy was caused by the coating used on the exterior which was essentially solid rocket fuel.
That theory has been largely discredited. There wasn't nearly enough reagents in the fabric to create a large thermite reaction. An oxyhydrogen explosion is the most likely explanation: there was probably a leak prior to the explosion, which allowed air to mix with hydrogen inside and surrounding some of the gas bladders. Also, a walkway ran through the bladders, which acted as an oxygen source once the bladders burst, as evidenced by flames being directed through the axial walkway.
> Hydrogen does not burn energetically, especially before it has been mixed with oxygen.
Drop the word "especially" and I might agree, but a mere party balloon of hydrogen mixed with oxygen in a stoichiometric ratio going off will sound like a rifle and rattle windows.
When I was young, I volunteered at a science museum who would, as part of their chemistry show, fill a balloon with hydrogen and ignite it off a tesla coil.
One time, we (~15yo kids) convinced the person giving the show (maybe...college age kid?) to also mix O2 in the balloon, instead of only H2.
The boom was so loud that management folks on the other floors sent people down to see WTF was happening. I don't think he got into (much) trouble, but he sure never did that again.
I don't know why this theory is repeated as though it's fact. The explanation that a lifting gas bag ruptured, mixing it's contents with the air seems a better fit to the witness accounts.
New footage shows the tail-fins catch fire before the gas-bladders erupted. Those tail-fins must, therefore, have been quite flammable. The video suggests that the trigger for the fire was the release of a large build up of static electricity on approaching proximity to the ground. An airship is essentially, an oversized Leyden jar, and such a build up would cause problems, even for ones using helium for lift.
The Hindenberg was also reportedly quite tail-heavy coming in for landing, which suggests a leak. If it was leaking at the tail and this was triggered by static discharge it would fit most of the facts.
I'd estimate that most people who died were trapped or unable to move. Those who were free to run and had enough "air" were very likely to survive.