"There is a solid theory now on why the Hindenburg caught fire.  There is a film about it too - I think it was on Netflix a few years ago.  Summary, IIRC:The pilot avoided a strong electrical storm by turning the rudder of the ship very, very sharply.  The twisting of the hull broke free a few interior stay cables inside the hull.  This must have caused a very small gas leakage somewhere on the membrane.  When the ship was coming in there was an electrically-charged atmosphere/situation with a nearby storm.  The ship was holding a huge amount of static energy potential ... when the ropes were dropped to the ground this energy was discharged, causing sparks that reached the hull and the escaping hydrogen.  "