I think he may be referring to "main story" as in what the big story will be when we look at this event years from now: 1) the deaths of ~10,000 people and wide

I think he may be referring to "main story" as in what the big story will be when we look at this event years from now: 1) the deaths of ~10,000 people and widespread destruction, or 2) a nuclear reactor incident in which the reaction was bungled at first but ultimately was not a catastrophe for the larger nation or world.