The naphtha and hydrogen gas leaked out from the gasoline reformer at the Southwest Petroleum as the relief-valve was operated after its repair.Although the source (Asian database ADRC) does not mention it, by looking at the fatalities it can be assumed that the mixture took fire and/or exploded,

As the airship approached the docking mast, it performed a sharp turn to face into the wind, which was shifting. The engines were run at full speed astern for about a minute to slow the airship. Dust came from the lines as they dropped to the ground, but the lines wetted in the light rain. Only the port line had been attached to a ground winch used for drawing the airship down to ground level for disembarking passengers and cargo. The starboard line was being handled by ground crew at the time of the fire. The nose cable had been lowered about 50 ft.