Thunderstorms had kept the Hindenburg circling for hours. When the giant airship finally turned in towards the mooring mast at Naval Air Station Lakehurst, New Jersey, on the evening of 6 May 1937, reporters, photographers and newsreel crews were waiting on the field. Radio reporter Herbert Morrison was recording. At 7:25 pm, flames appeared near the tail.

In roughly half a minute, the largest aircraft of its day was a burning skeleton on the sand. Thirty-six people died: 13 passengers, 22 crew and one man on the ground. Because the cameras were already rolling, the whole world saw it, and the age of the passenger airship ended with it.

The Pride of the Zeppelin Company

The Hindenburg was built to carry passengers across the Atlantic in hotel comfort. It had a larger diameter than the earlier Graf Zeppelin and carried roughly twice the lifting gas, driven by four Daimler-Benz diesel engines. Passengers had cabins, a dining room, a lounge and a promenade with large observation windows that looked straight down onto the ocean.

It was also filled with hydrogen. According to Airships.net, the ship was originally designed to use non-flammable helium, but the United States held a monopoly on the gas and the Helium Control Act of 1927 banned its export. The Zeppelin company used hydrogen instead, as German airships always had, and relied on careful procedures to keep sparks away from it.

Thirty Seconds at Lakehurst

The Hindenburg left Frankfurt on the evening of 3 May 1937 with 36 passengers and 61 crew. Headwinds slowed the crossing, and when it reached Lakehurst on 6 May, afternoon thunderstorms forced it to wait. Captain Max Pruss took the ship over Manhattan while the weather cleared, and landing clearance came at 6:22 pm.

At 7:25 pm, with mooring lines dropped and the ship about 295 feet up, fire broke out near the stern. Within seconds it had spread through the hydrogen cells. The tail fell, the ship tilted, and the burning hull came down with the bow pointing upwards. Four newsreel teams, from Pathé News, Movietone News, News of the Day and Paramount News, filmed it. Herbert Morrison kept talking into his microphone.

British Pathé's 1937 newsreel footage of the Hindenburg disaster at Lakehurst. Video: British Pathé

How Anyone Survived

The remarkable thing about the Hindenburg is not that 36 died, but that 62 of the 97 people aboard lived. The ship was already low, close to the ground. Many survivors jumped from windows as the hull sank towards the sand, and ground crew ran towards the fire to pull people clear. Most survivors were badly burned.

Werner Doehner was eight years old. His father and sister were killed. His mother threw him and his brother out of a window, then jumped after them, breaking her hip. He needed nine skin-grafting operations. Doehner became the last living survivor of the disaster and died in November 2019, aged 90.

What Lit the Fire?

Both the US Commerce Department inquiry and the German investigation concluded that the most probable cause was leaking hydrogen ignited by static electricity. The theory goes that the airship had built up an electrical charge flying through stormy air, and that when the wet mooring lines touched the ground, a spark jumped near a hydrogen leak at the stern. Neither the leak nor the spark was ever directly proven.

Other explanations have been argued for decades: a bracing wire snapping during the sharp final turns and ripping a gas cell, a flammable aluminium-based coating on the outer fabric, a backfire from an engine, and sabotage. Official investigators rejected sabotage for lack of evidence. The static-electricity explanation remains the most widely accepted, but the debate has never quite gone away.

A modern investigation into the competing theories behind the Hindenburg fire. Video: Deconstructed

The End of an Era

The Hindenburg was not the deadliest airship accident. The crash of the US Navy's USS Akron in 1933 killed 73, and Britain's R101 disaster in 1930 killed 48. But neither was filmed from the ground as it happened. The Hindenburg newsreels played in cinemas around the world, and public confidence in the passenger airship collapsed almost overnight.

Its sister ship, LZ 130 Graf Zeppelin II, never carried fare-paying passengers. Within a few years, long-range flying boats and then landplanes had taken over the transatlantic routes the Zeppelins had pioneered. Morrison's words are still how most people remember the airship age: not the luxury cabins or the quiet crossings, but thirty-odd seconds of fire at Lakehurst.

HISTORY examines what really caused the Hindenburg disaster. Video: HISTORY

Sources: Wikipedia (Hindenburg disaster, Werner Doehner), Airships.net, Royal Society of Chemistry (Education in Chemistry)