Why did the Hindenburg crash?

The world’s largest airship crashed in Lakehurst, N.J., in 1937, killing 35 passenger and one of the ground crew, and giving life to rumors that a saboteur or maybe the Nazis blew it up. Seventy-six years later, researchers think they’ve solved the puzzle. They say hydrogen from the blimp leaked into a ventilation shaft where static electricity from an electrical storm ignited it. When the ground crews grabbed the ropes and grounded the ship, it exploded.