Those who are proposing the 'leaking fuel' ohmygodwereallgoingtodie hypothesis may be forgetting that jet fuel is kerosine based, not gasoline based. For this they can thank Lord Brabazon of Tara, the Aviation Minister in Britain when the jet age dawned. His US counterparts wanted to use wide cut gasoline as it was more readily available, but the Brits wanted the safer fuel. Lord Brabazon invited the U.S. team to stand in a puddle of their fuel and toss lit matches into it, while he did the same with Kerosene. The U.S. team declined the offer and, safer, kerosene based fuels became standard in civilian use, although the US military persisted with wide cut gasoline until the mid 90s.