There is an interesting scientific article in Nature (link), that discusses a megaton-sized city-busting event that took place 3600 years ago. Something exploded in the air and completely levelled a civilisation in ancient Israel. The city (which included a five story palace) was pulverised and melted down to the height of a couple of bricks. The airburst is thought to have destroyed everything within a fifteen mile radius!
Evidence is presented that this was not just a nasty earthquake but something like a larger edition of the Siberian Tunguska event, that targetted a centre of civilisation rather than a bunch of trees.
An interesting read, and a good basis for some of the Biblical fantasies.