[ZGuy]

The most accepted theory is that static electricity from the day's storms led to the ignition of the hydrogen.

I believe this is true among those who have only cursory knowledge of the incident. The research from eighty years ago and also much more recently indicated that the aluminized fabric was the major factor in the disaster.

[SoCal Pubbie]

Yes, the outer cotton fabric, coated in highly flammable aluminized dope, ignited, acting as a spark to set off the hydrogen. German scientists knew it righth after the tragedy, but covered up their findings.