they blew up
Hydrogen used to be used in airships.
because hydrogen used to be in those airships and since hydrogen is flammable it was very dangerous
There never were hydrogen powered airships. Hydrogen provided lift, not propulsion. Propulsion came from combustion engines using diesel or gasoline.
Hydrogen
Hydrogen and helium are two elements that are kinda-sorta interchangeable in airships.
Hydrogen was once used to fill airships. Quite dangerous due to how flammable it is.
Hydrogen airships can vary in size, but most commercial airships are around 200 to 250 feet in length. However, historical airships like the Hindenburg were much larger, at approximately 800 feet long.
Hydrogen is highly flammable, posing a significant safety risk for airships. This was highlighted by disasters such as the Hindenburg crash in 1937. As a result, the use of hydrogen in airships was phased out in favor of safer alternatives like helium.
That'd be hydrogen.
The Hindenburg disaster
Helium has replace hydrogen in airships
Helium is inert. Will not burn like hydrogen does so well.