I didn’t see a thread here, and the fact that the Russians are giving conflicting information and seem to be going out of their way to cover this up, despite massive evidence to the contrary, says to me that this was much, much worse than anyone not directly in the know can imagine.
Rachel Maddow devoted the first segment of her program to this story - about how they said 5 were dead, and then 2 were dead, and that they were nuclear scientists, and then they were just people who worked there, and similar things going on regarding evacuations of nearby towns, etc.
This is probably the most reliable link I can find.
This (allegedly) happened before the cover-up kicked into high gear.
You can see the shockwave in this video. I’d like to know the kilotonnage of that explosive force.