Over the years, may hypotheses about how the fireplace aboard the Hindenburg started were proposed. One of many more popular theories in conspiracy theory circles is that the airship was sabotaged, by anyone from communists to Adolf Hitler. This week, a brand new documentary at the disaster will endorse one of the crucial more mainstream explanations for the explosion.

According to a report by The Independent, the brand new documentary, to air Thursday at the U.K.’s Channel 4, states that static electricity might have set the zeppelin ablaze. On this scenario, an electric storm had charged the airship while gas had somehow leaked into the Hindenburg’s ventilation shafts. Crew members who took up the zeppelin’s landing ropes could have grounded the ship’s frame, but not its skin, causing the spark that result in the fireplace on the tail end of the ship.

According to the Independent, a gaggle of experts led by aeronautical engineer Jem Stansfield set fire to various scale models of the Hindenburg before reaching this conclusion. The research team recreated different scenarios for the disaster using the replicas, and tested multiple theories, including sabotage.

The Hindenburg, a German passenger airship, caught fire on May 6, 1937 over an airfield on the Lakehurst Naval Airstation in New Jersey. The blaze took down the airship in under 20 seconds, causing the deaths of 35 of the 97 people on board the ship. Newsreel footage of the disaster, featuring commentary from radio reporter Herbert Morrison, has become famous and is the origin of the popularization of the phrase, “oh the humanity!”