Just look at Rome ...

And you'll see the same 'similarity of decline' here as you did in the waning years of the Empire:

...

Such questions are becoming common across the nation as water and sewer systems break down. Today, a significant water line bursts on average every two minutes somewhere in the country, according to a New York Times analysis of Environmental Protection Agency data.

In Washington alone there is a pipe break every day, on average, and this weekend’s intense rains overwhelmed the city’s system, causing untreated sewage to flow into the Potomac and Anacostia Rivers.

State and federal studies indicate that thousands of water and sewer systems may be too old to function properly. [my em]

...

When a society can't fix its basic infrastructure, the fall is well on its way.

Thanks to Atrios for the link.