[nightmunnas]

Probably proximity to home country mixed with the number of victims that are of proximal origin to ones own country/region.

[sandrobfc]

Yes, relevancy as proximity to our country/region. I think I would first hear about a disaster that killed one single person from Portugal (as a Portuguese myself) anywhere in a world than one that killed fifty from any other nationality (outside of Europe and North America).

That would be different for people around the world according to their country and region.