It would take a megaton range nukebomb to flatten a township, and of course there are degrees of lesser damage farther out. Townships are 6 by 6 miles. This meteor was apparently 5000 times smaller than a megaton. Or one five-thousandth as big depending on your politics. Neither Nagasaki nor Hiroshima were totally destroyed by the nukebombs, although devastation was essentially complete inside a certain radius.