Remember, the original gunpowder, which we now call black powder, is considered an explosive. It was used in blasting rock prior to dynamite. And it could be set off by static electricity. Lightning - yikes!
I toured a mine reopened in Virginia City, Nevada. The old miner who opened it back up told me of the stash of century-old blasting powder (version of black powder gunpowder). He said everybody was nervous and the street was closed while they removed the powder. The entrance to the mine is through a nice old bar!
“There’s a rattle in my glove box,
A Federal twelve-gauge slug.” – Adam Carroll in song Porter Wagoner