Worldwide catastrophes leave worldwide evidence. There is no worldwide evidence for a worldwide flood that covered the mountains. There is evidence of local floods that would have involved to whole of a primitive tribes world. There is the Gilgamesh Epic that predates the Biblical stories. There are evidences of worldwide catastrophes in the geological time scale, but they occurred many millions of years ago. Long before there were humans. Humans wrote the Bible. Humans who were extremely ignorant by todays standards.