Helium, the gas that the airship Hindenburg was designed to be filled with, but could not be, due to an American embargo on export of Helium to Nazi Germany. The result was the death of many onboard the Hindenburg, when the flammable hydrogen that was used instead ignited and burned upon approach to the mooring in New Jersey.
As an infant, my girlfriend's father was scheduled to be onboard the Hindenburg, but he never boarded, due to intervention by Joseph Stalin.
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Darron, temporary Desert Rat