Disaster; a serious disruption of the functioning of a community, came to English via old French where it was ‘désastre’, which is basically the same word with a bit of an accent.
It got to French from Italy via the Roman empire, the Latin word was ‘disastro’ which in turn was from the Greek word ‘disaster’. After travelling through time and across languages it is now the same word as we started out with. The word was made of two greek words ‘dis’ meaning ‘bad’ and ‘astro’ meaning star. The Greeks were blaming the alignment of the stars for the terrible circumstances.