[Mind's Eye] When is a natural disaster a natural disaster?

[paradox]

Listening to some tv coverage of the humanitarian disaster (yet again)
unfolding in the Horn of Africa, i learnt from a knowledgeable
commentator that in order to respond appropriately, global aid and
humanitarian quasi-governmental organisations actually have to
classify a disaster by a fatality ratio; which got me thinking. When
is a natural disaster a natural disaster?