Hydrogen was the volatile gas responsible for the Hindenburg disaster in 1937. The German airship LZ 129 Hindenburg was filled with hydrogen to provide lift, and leaking hydrogen fueled the enormous fire that destroyed it during its landing approach at Lakehurst, New Jersey, on May 6, 1937.
The Hindenburg was a rigid airship built with 16 gas cells containing hydrogen. Hydrogen is extremely light and provides strong buoyancy, but it is also highly flammable when mixed with oxygen. The fire consumed the airship in roughly 90 seconds, killing 35 of the 97 people aboard and one person on the ground.
The exact ignition source remains debated. The leading historical explanations involve a hydrogen leak followed by ignition from static electricity, although structural failure, electrical discharge and other possibilities have also been discussed. Thus, hydrogen explains what fed the fire, while the precise spark that started it is a separate question.
Another common misconception is that the Hindenburg exploded like a sealed bomb. It was a large, lightly pressurized airship; the hydrogen burned rapidly as it escaped and mixed with air.