Just stubby pencil work here because I'm up at entirely the wrong hour and this might help me go back to sleep.
Envelope volume of the Goodyear blimp is ~8.5e6 liters.
Density of hydrogen at STP is ~0.09g/L. If we filled the Goodyear blimp with that we'd have ~765kg of hydrogen gas. Let's round up to cover the slight operating pressure and say we have 800kg of hydrogen.
Energy density of hydrogen is very high, 141MJ/kg. Energy density of Jet A is ~45MJ/kg.
So our hypothetical blimp has the equivalent of 2600kg of Jet A on board.
The Goodyear blimp only holds 8 passengers plus two pilots. A similarly sized jet would be the Learjet 60. It holds 3500kg of fuel.
So, most jets probably have more on takeoff and less on landing.
The Hindenburg carried around 200k m³ of hydrogen, or 18,000kg, storing 2.54 PJ of energy, or equivalent to 56,400 kg of jet fuel. A 747 can carry more than four times that (240k-ish); an A320 or 737 carries slightly more than half (25k-ish). The Hindenburg only carried some 70 passengers, though.
There is an important distinction in hydrogen fires from jet fuel ones: the moment it is released hydrogen escapes upwards, taking any fire with it. Jet fuel on the other hand tends to pool downward, while releasing its vapor (the part that actually burns) upwards. So it tends to spread fires in both directions.
So a hypothetical of a zeppelin crashing into a building might light that building on fire, but most of the hydrogen from the vehicle would escape upwards into the atmosphere without having contributed to the building's fire.
