For 75 years, scientists have wondered what caused the Hindenburg, the world's largest airship, to catch on fire as it landed during a thunderstorm in Lakehurst, New Jersey on May 6, 1937. This past Sunday, the Discovery Channel's Curiosity tackled the mystery, building the largest replicas of the airship—one-tenth of the original's size—to test out a few of the most popular theories. You can check out video of one of the builds below.
The Curiosity team used the scale models to test out four theories behind the Hindenburg's destruction: that it was a bomb; that a lightning strike ignited the ship's leaking hydrogen; that it wasn't hydrogen, but the ship's skin, that ignited; or that it was St. Elmo's fire—a phenomenon where tall objects in storms seem to produce their own lightning sparks—that caused the leaking hydrogen to ignite. Then they compared the footage from their tests against the original footage of the crash. Below is the video of their setup for the bomb test.
Their final verdict? That St. Elmo's fire at the rear of the Hindenburg was sucked into the ship's vents, causing the leaking hydrogen to ignite and bringing the craft down in just 34 seconds.