I really liked the TV show In Search of... as a kid in the 1970's. I have enjoyed re-watching some of the old episodes and lovingly critiquing, with the benefit of 30 years of hindsight, some of the explanations proffered for the mysteries the show examined. In Search Of... once did an episode, which first aired in February 1981, examining the possibility that the Hindenburg disaster may have been the result of sabotage. You can watch a 10 minute segment from this episode by clicking HERE. After explaining that the United States had refused to sell Nazi Germany the far less combustible helium gas for which the Hindenburg was originally designed, narrator Leonard Nimoy adds, "The reason for the fire that consumed the airship was obvious: the 7 million cubic feet of volatile hydrogen gas that was contained in the hull. The reason why the fire started has been a source of controversy to this day. Was it accident or sabotage?"
The suggestion that there remained in 1981 a significant controversy about whether "sabotage" caused the accident may have been a little disingenuous. While sabotage was suggested as a cause in the days immediately following the tragedy, an official American inquiry later in 1937, which included a high-level German delegation, concluded that the fire was set-off by some sort of accidental electrostatic discharge which ignited the hydrogen, perhaps because of a puncture in the airship's outer, canvas skin. A one hour episode of the National Geographic Channel series "Seconds From Disaster" that first aired in 2005 (which you can watch on You Tube in its entirety; part 1 is HERE), came to this same conclusion as well. The less sexy controversy that lingers to this day (well, really, the "uncertainty") concerns the precise cause of this electrostatic build-up and how, specifically, it ignited the hydrogen inside.
Nimoy then goes on to note at the very end of the episode that because helium is now freely available, this type of travel is much safer than it was in 1937. A bullish Goodyear official is then interviewed aboard a blimp. He readily confirms their safety and adds enthusiastically about the commercial potential of these airships, "they're far more economical than aircraft." Leonard Nimoy then ends the show on a hopeful, but hopelessly incorrect, note (while impressive conceptual drawings of gigantic passenger blimps are flashed on screen), "Perhaps the airship business is about to pick up where the Hindenburg left off."