IIRC, Hindenburg was supposed to have a thin outer helium layer surrounding the hydrogen providing the bulk lift, as a safety measure to inertize it, in case of leaks. But due to a wartime shortage of helium, the outer layer was filled with hydrogen as well, compromising safety. The original design was sound, but corner cutting caused the disaster.
The thing is that hydrogen's buoyancy is so high that it lifts up above the dirigible very quickly once released. So fire risk isn't really that great in terms of burns.
The bigger problem is the "lack of buoyancy" of the rest of the dirigible (and the impact with the Earth affecting the passengers). So that's a bigger issue to address, engineering-wise.
