On May 6, 1937, just minutes before 7:30pm, a German zeppelin called Hindenburg was approaching a mooring mast at Lakehurst Naval Air Station in New Jersey, completing its three-day expedition from Frankfurt, Germany with 97 souls aboard. This rare event⁠—the first trans-Atlantic Zeppelin flight to the U.S. that year⁠—had been heavily publicized in advance, so numerous reporters and journalists were present to record the grand occasion.

What followed was a disaster of dramatic proportions, which largely condemned zeppelins to the scrapheap of history. Herbert Morrison, a radio reporter present to record the event, uttered the anguished words which have become part of our culture’s lexicon⁠—Oh, the humanity!⁠—as the German airship was rapidly consumed by flames, plunging into the crowd of people below.

There are still a number of unknowns in the story of the Hindenburg disaster, including the source of the spark which set the dirigible alight. But it is certain that the accident could have been avoided had the Hindenburg’s builders not been forced to make some design changes during its construction.

Hindenburg was (and remains) the largest air-going craft ever built. It was 804 feet long⁠—more than twice the length of an American football field⁠—and held over seven million cubic feet of hydrogen gas. Its original design called for non-flammable helium, but only the United States possessed the rare gas in usable quantities, and an embargo was in place against Germany because of the American government’s disapproval of the new Nazi party. Consequently, the design was modified to use hydrogen instead. That change proved to be the fatal flaw which brought the Hindenburg down, and with it, the entire zeppelin industry.

Before the Hindenburg, hydrogen-filled zeppelins had been in use for many years, with an outstanding record for safety. Germany’s earlier Graf Zeppelin had successfully circumnavigated the globe, and the Hindenburg’s immediate predecessor, the Graf Zeppelin II, had logged almost one million miles of safe travel including many Atlantic crossings and flights through thunderstorms. The engineers had taken a number of safety precautions to prevent hydrogen fire, including a special coating to prevent electric sparks.

On May 6th, as the Hindenburg arrived in the United States, the weather at the mooring mast in Lakehurst, New Jersey was restless and did not allow for a safe landing. In the meantime the airship’s commander Max Pruss decided to slow down over New York City, affording his passengers spectacular views of downtown New York City, the Empire State Building, Times Square, and the Statue of Liberty. He commenced a pattern of flying in large circles over the area until he got word from from the commanding officer at Lakehurst: “Conditions now considered suitable for landing.” Eleven minutes later, the first message was followed with another: “Recommend landing now.”

It was dusk as Hindenburg began its descent into Lakehurst at about 7:00pm. Radio reporter Herbert Morrison describes the aircraft as it moved towards the mooring mast:

“Now the field, as we thought active when we first arrived, has turned into a moving mass of cooperative action. The landing crews…their posts…and orders are being passed along, and last-minute preparations are being completed for the moment we have waited for so long.””The ship is riding majestically toward us like some great feather, riding as though it was mighty good…mighty proud of the place it’s playing in the world’s aviation. The ship is no doubt bustling with activity as we can see; orders are shouted to the crew, the passengers probably lining the windows looking down at the field ahead of them, getting their glimpse of the mooring mast. And these giant flagships standing here, the American Airline flagships, waiting to direct them to all points in the United States when they get the ship moored.”

“There are a number of important persons on board, and no doubt the new commander, Captain Max Pruss, is thrilled, too, for this is his great moment, the first time he’s commanded the Hindenburg. On previous flights, he acted as Chief Officer under Captain Lehmann.”

“It’s practically standing still now. They’ve dropped ropes out of the nose of the ship, and it’s been taken a hold of down on the field by a number of men. It’s starting to rain again; the rain had slacked up a little bit. The back motors of the ship are just holding it, just enough to keep it from ⁠—”

“It burst into flames! Get out of the way! Get out of the way! Get this, Charlie! Get this, Charlie! It’s fire and it’s crashing! It’s crashing terrible! Oh, my! Get out of the way, please! It’s burning, bursting into flames and is falling on the mooring mast, and all the folks agree that this is terrible. This is the worst of the worst catastrophes in the world! Oh, it’s crashing…oh, four or five hundred feet into the sky, and it’s a terrific crash, ladies and gentlemen. There’s smoke, and there’s flames, now, and the frame is crashing to the ground, not quite to the mooring mast…Oh, the humanity, and all the passengers screaming around here!”

“I told you… I can’t even talk to people…around there. It’s⁠—I can’t talk, ladies and gentlemen. Honest, it’s just laying there, a mass of smoking wreckage, and everybody can hardly breathe and talk… I, I’m sorry. Honest, I can hardly breathe. I’m going to step inside where I cannot see it. Charlie, that’s terrible. I⁠—Listen folks, I’m going to have to stop for a minute, because I’ve lost my voice… This is the worst thing I’ve ever witnessed…”

Once the flames appeared, the 231 men working on the field below scattered, running for cover. These men were the “humanity” that Herbert Morrison famously feared for after the fire erupted. Passengers leaped out of the windows of the lurching, rapidly descending airship as its hydrogen gas fed flames that reached hundreds of feet into the air. The fire was estimated to reach 3,713 degrees Fahrenheit, well beyond the melting point of the aluminum girders.

Only thirty-seven seconds after the first sign of trouble, the mighty dirigible was a heap of flaming ruins on the ground. Amazingly, sixty-two of the ninety-seven passengers escaped with their lives, including the Hindenburg’s captain. Thirty-five people on the aircraft were killed, as well as one member of the ground crew⁠—or the “mass of humanity” as Herbert Morrison had described them before the accident, hence his famous cry of distress.

The cause of the fire has never been established with any certainty, though there are numerous theories. The official investigation concluded that a hydrogen leak was ignited by a spark of static electricity, but many people did not accept that explanation. Most notably, a theory of sabotage was put forward by Hugo Eckener, the former head of the Zeppelin company, a theory which was also backed by the Hindenburg’s commander Max Pruss. But no evidence was ever found to support this hypothesis. Some also suspect that a bracing wire may have snapped and punctured one of the hydrogen bags, allowing the gas to be released and easily ignited. But doubt is thrown on the likelihood of a slow leak since the naturally odorless hydrogen gas had been odorized with garlic so that any leaks could be detected, yet no survivors reported detecting this odor at any time.

Another theory put forward by Addison Bain⁠—former manager of NASA’s hydrogen program⁠—suggests that the compound used to waterproof the outer surface of the Hindenburg was chemically reactive, and that it was the fabric which burned rather than the hydrogen. Its coating contained iron oxide and aluminum, which are sometimes used as components of solid rocket fuel. Bain went so far as to say that “The Hindenburg was literally painted with rocket fuel.” But the two compounds were separated by a layer of material which should have prevented any reaction, and experiments to test the theory found that it would have taken about forty hours for the Hindenburg to burn if the fire had been driven by a fabric fire, much longer than the thirty-seven seconds it actually took.

A. J. Dessler⁠—former director of the Space Science Laboratory at NASA’s Marshall Space Flight Center⁠—discredited the so-called incendiary paint theory, and put forward a simpler hypothesis: the fire was sparked by lightning. The Hindenburg had been struck by lightning multiple times during its operational life, and it had not previously caused any serious damage. But on that May evening, the crew of the Hindenburg was venting hydrogen in preparation for landing, creating a column of combustible hydrogen/oxygen gas directly over the airship. Witnesses did not report any lightning or stormy weather in the area at the time of the disaster, but some forms of lightning (such as positive lightning) can strike from a seemingly clear sky.

Some retellings of the disaster claim that it occurred on the Hindenburg’s maiden voyage, but that isn’t so. The giant zeppelin had been in use for over a year before it burned, sometimes on trans-Atlantic voyages, and other times flying low over Germany, emblazoned with giant Nazi swastikas and spewing propaganda through a loudspeaker. Before the disaster, the giant airships were often used by the Nazi party as symbols of German power and technical prowess, including a flight over the stadium at the 1936 Olympic Games in Berlin, just moments before the arrival of Adolf Hitler.

Hindenburg memorial at Navy Lakehurst
Hindenburg memorial at Navy Lakehurst

Despite the excellent safety record of zeppelins, the horror of the Hindenburg scene destroyed any chance of a future for rigid airships. High-profile zeppelin-oriented projects⁠—such as the planned airship dock atop the Empire State Building⁠—were abandoned. Less than four years after the Hindenburg disaster, the last of Germany’s zeppelins was dismantled so its valuable aluminum could be repurposed for implements of war. Today, the site of the Hindenburg disaster at Navy Lakehurst is marked with a gondola-shaped pad at the precise location where it touched the ground.