Addison Bain, a former NASA scientist and an expert on hydrogen, has made a very good case that the Hindenburg tragedy was not due to the flammability of hydrogen, but rather the extremely flammable coatings on the skin of the airship which were ignited when electrical charges building up on skin caused a spark. There was a TV show a couple of years ago where Bain demonstrated this using a piece of the original skin of the Hindenburg. He applied a spark and it went up in flames. Apparently, when hydrogen burns, the flames are largely invisible.
ReferenceThe Hidenburg wasn't made up of hydrogen, that was helium.
