Well, Arco, ID had a nuclear power plant disaster a couple of years after it opened. I think it was in January of 1958/9.
All 3 persons on duty during that shift died; I read that the cause was error of human operator/s.
Just trying to make the thread more complete and informative.
I heard early examination of the site showed the two people who had died.
Later examination discovered the third body - pinned to the ceiling with a fuel control rod...