The Soviets had a similar massive disaster with their space program: https://en.wikipedia.org/wiki/Nedelin_catastrophe
The story behind the story is that the Nedelin was vainfully confidant enough to watch the test close up, maybe as a way to sort out those not “with the program”, but as such, all the suck-ups as well as the ones afraid of Nedelin more than the hurriedly built rocket, joined Nedelin up close and personal.
Yeah, but that only killed people who were in the USSR space program.
The NK nuke program has apparently poisoned water supplies out to a considerable distance from the testing location due to radionuclide leaching into the groundwater aquifer, as well as by atmospheric releases.
China is very unhappy with NK because of radiation that has come across the border into Liaoning and Jilin provinces. Chinese people have been warned not to eat local produce, including vegetables grown in private plots, balcony gardens, etc.