Over the years, America has experienced many disgraceful boondoggles that wasted public funds, but few if any of these travesties can top the notorious Big Dig in Boston.

At last report, the cost of the tunnel through a heavily traveled section of downtown Boston had topped $15 billion and is still causing a deadly drain on local treasuries. The project was delayed many times as incompetence, fraud, graft and bad management drug out the completion and kept costs soaring.

Now The Dig is back in the news, and it’s not good.

Contractors are going to pay more than $450 million to settle a lawsuit with the state of Massachusetts over a fatal tunnel collapse and to cover leaks and design flaws. Apparently the ceiling collapse that killed one woman has been repaired but leaks and other problems persist, causing fear among those who must travel the route.

Bechtel/Parsons Brinckerhoff, the consortium that oversaw the design and construction of what has become the nation’s costliest public project ever, has agreed to pay $407 million. U.S. attorney Michael Sullivan announced the deal this week. Several smaller companies are to pay some $51 million collectively.

Here we have the nation’s costliest and most complex highway project that was prepared and built in full public view, yet dishonesty and foolishness caused the cost to balloon far beyond twice the estimate. It was not a case of getting the job finished and then finding the flaws. Didn’t anyone ever take charge and look into the cash drawer? Or under the rug where the criminals hid their theft?

The Big Dig became a financial and public safety disaster from the first time there was any kind of dig or concrete-pouring and one public official after another stood around and let it all happen, always blaming someone else for the latest debacle. Who or what has jurisdiction now?

These days, it is not difficult to look back at a number of U.S. public projects that have been disgusting debacles from the standpoint of cost overruns and mismanagement. At this time, Boston’s infamous Big Dig may top all those frustrating lists, but it’s hard to predict what the future may hold.