This is a four-character idiom (成语) meaning that everything is completely gone, vanished without a trace. You use it when something — possessions, hopes, records, or even cities — has been entirely destroyed or lost, often after a disaster, war, or major setback. The literal components (荡 'vanish', 然 '-ly', 无 'without', 存 'remain') build the image of 'transformed into nothing, nothing remains'. It carries a sense of finality and is more dramatic than 没有了.