Dirigible accidents cost hundreds of lives in the early 20th century, but Hermann Doehner was confident enough to take his family on a return trip across the Atlantic in the hulking flagship of the Zeppelin company. The Hindenburg was no ordinary airship. At 245m long, it was more than twice the length of a football pitch and could fly at 80mph, taking a mere two and a half days to travel between Europe and America.

Admittedly, nonflammable helium would have been a safer lifting gas than hydrogen, but the monopoly supplier, the United States, had banned its export to prevent exploitation for military purposes. Securing a commercial exemption was complex and costly. Indeed, the Hindenburg, a Nazi propaganda tool since its maiden voyage in 1936, had swastikas on its tail fins.