[tbontob]

Yeh, I think you are right, it was the Hindenburg.

I think the reason the Hindenburg did not explode was because it was not in a confined space and oxygen was not mixed with the hydrogen.

As the hydrogen and the oxygen were separated, the burning essentially took place on the periphery and moved inwards as the oxygen moved inwards.

Also air is only about 20% (21%?) oxygen, it is diluted and the rate of burning is much reduced than if it was pure oxygen.