I note two things of interest. One is that the this painting ("the little") seems to show many more people on the ramps. Perhaps this is the one containing the 7000?
The second thing is that I see rubble falling from the left edge of the gap on the sixth level-- falling all the way to the bottom where it lands in a water-fall-like jostling of rock and dust. I have read that Brueghel in his latter years worked on painting falling objects. No easy trick, as some sense of motion is needed to show the fall. Apparently, he felt this was not working for him, and in the tower of my puzzle, this effect is not used. Or if the the smaller was painted after my picture, it may have been exclusively to try the falling rubble effect.
There is a political context to develop concerning the tower depiction. One notes early on that the ships in the harbor, the people, the houses, seem more of Antwerp than Babylon. I disagree with the wikipedia article that sees the tower as an object of new construction so ineptly done, that it is doomed to fail. It is obvious to me that masses of rubble have coalesced over centuries into what looks like the live rock of a mountainside, and thus the painting shows a tower that was built long ago, and has partially collapsed. The ruler in the picture, a Nimrod dressed as a european king, is trying to re-build the tower, and Jehovah still watches from his cloud.
I delivered too many Chicago Tribunes as a youth not to recognize the political cartoon beneath this work of art.
What I call the third painting is actually the first. I found this on the Web Gallery of Art:
"Bruegel painted the subject of the Tower of Babel three times. The first version (now lost), very small and painted on ivory, is mentioned in the inventory of Giulio Clovio, the famous miniaturist, whom Bruegel met and collaborated with in Rome in 1553."
It is worth a look at the web gallery images using their viewer to look at small patches of the tower painting in much greater detail. It is amazes me how much exists at the level that you would totally ignore until you have seen it enlarged.
That will get you there, but you may have to jockey about a bit to get to the tower images, since the website server and links have changed on the site.