As luck would have it,
“13 lucky miles away as the crow flies”
from where the acetylene/oxygen gas in the toy ballon was ignited
there were Thermo-nuclear Hydrogen bombs in storage
plus three varieties of nerve gases in aerial bombs, artillery shells, and mortar bombs.

“There must have been quite high security guarding those”
you might think.

In another odd accident a few years later,
I was present when when the US Army Colonel in charge of that storage area
was told by a Railroad employee that the security gate where the railroad entered the storage area
had been crashed into and destroyed 6 days earlier
by sole fault of the railroad crew, and the railroad was willing to totally pay for its replacement.

The Colonel got a weird look on his face and turned around and picked up a notebook,
turned pages looking at entries,
asked the railroad employee again:
what date and time did this gate get destroyed?

The Army guards had been too lazy to walk down and carry out their duty to inspect that gate.

Years later a special plant was built to chemically neutralize the nerve gas filled weapons.
Pipe welds in that plant were to be 100% x-rayed.
The x-rays that showed defective welds were faked to show good welds.
All the welds had to be ground out and re-done at great time delay and expense.

Ignorance is bliss.
It probably is even worse than you suspect.