These added to the accumulation, which increased the faster because the foundations of the ancient bridges held it like piles driven in for the purpose.

And before this the river had become partially choked from the cloacae of the ancient city which poured into it through enormous subterranean aqueducts and drains.
After a time all these shallows and banks became well matted together by the growth of weeds, of willows, and flags, while the tide, ebbing lower at each drawing back, left still more mud and sand.

Now it is believed that when this had gone on for a time, the waters of the river, unable to find a channel, began to overflow up into the deserted streets, and especially to fill the underground passages and drains, of which the number and extent was beyond all the power of words to describe.

These, by the force of the water, were burst up, and the houses fell in.
For this marvellous city, of which such legends are related, was after all only of brick, and when the ivy grew over and trees and shrubs sprang up, and, lastly, the waters underneath burst in, this huge metropolis was soon overthrown.

At this day all those parts which were built upon low ground are marshes and swamps.