There are dozens of theories about what caused the calamitous crash of the Hindenburg on May 6, 1937. But what really happened? In this episode of Curiosity, a team of aeronautical engineers sets out to see which theory is correct by building three perfectly accurate 50-foot replicas of the ill-fated airship. Those who tune in will get to see these experts put the leading theories to the test and find out what really destroyed the Hindenburg.