Unlike the Germans, Americans were under no such constraints, as contemporary newspaper accounts and declassified FBI files show. While the FBI didn’t formally investigate the Hindenburg incident, it assisted in the U.S. Commerce Department’s inquiry and became a contact point for citizens with theories to share.
While many correspondents suggested technical explanations for the disaster, the ones who favored sabotage showed the American imagination in full flower.
Many suggested that anti-Nazi elements were responsible. Those included communists, anti-Nazi Germans, Jews and Spaniards presumably angered by Germany’s support for the fascist leader Francisco Franco.
At least one correspondent suggested it was an inside job, that the Nazis themselves had blown up the Hindenburg for the insurance money.
The conspiratorially inclined also had a variety of theories regarding the means of destruction. An incendiary bullet fired from the ground was one possibility. (The FBI examined some suspicious footprints at one point but found nothing.) Another theory suggested a small plane had fired on the Hindenburg from above. One letter writer insisted it had been shot down by a New York City police lieutenant on the orders of Mayor Fiorello La Guardia.
The most common suspicion, though, was that a bomb had been hidden somewhere within the ship’s vast interior, ready to be activated by either a timer or a change in barometric pressure.
One sabotage theory focused on an American passenger named Joseph Spaeh (or Späh).
A German steward reported that he seemed suspiciously aloof and “unsympathetic to the airship travel.” It also happened that Spaeh was a professional contortionist and acrobat, useful talents for climbing around the ship’s interior structure and planting a bomb. At the urging of the base’s naval commander, the FBI checked out Spaeh and found nothing to incriminate him.
Decades Later, a New Suspect Emerges