BTW, unlike First World War era Zeppelins, the Hindenburg was designed to use helium. But only the USA had a lot of helium and FDR considered it a strategic recourse. So no sale to Nazi Germany.
But Hitler felt he needed the PR of the world's largest airship, so he ordered it to go ahead with hydrogen. And it made several trips with no mishaps.
I have never understood the incredible preoccupation with the Hindenburg. Very few people died in the tragedy, but because it was a spectacular explosion of a huge 800’ long airship caught on camera, it has spurred countless books, films, speculation, etc. I have been a huge airship buff all my life. There were far more tragic and fascinating crashes involving British and American dirigibles and they do not engender near the interest.