When the Hindenburg was designed in 1931, its makers made the fateful choice to use hydrogen instead of helium to set the blimp aloft. Hydrogen was cheaper and more readily available but had the nasty side effect of being highly flammable. That proved to be a problem in 1937, when the famed blimp caught fire and crashed in just 36 seconds, spelling the end to the hydrogen blimp. Most current blimps, including the famous Goodyear ones, are powered by far less volatile helium.
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