The hydrogen was retarded to begin with. Hydrogen will combust anywhere from 5% to nearly 80% by volume. The thing should have been a hydrogen-helium mix. The Hindenburg was an absolute nightmare-waiting-to-happen in the exact same way Titanic was (minus the flamable skin, mind you, although the sulfur-brittle steel came close).

The Zeppelin corporation wanted to use helium, but deriving it was new technology held almost exclusively by the Americans, who refused to sell it to Hitler's gang.

BOOM!

On the other hand, Graf Zeppelin made her historic 'round-the-world flight with no major problems.