When a collision closed Southwest Pass shipping lanes for a few days last week, the Mississippi River Gulf Outlet (MRGO) was not a lot of help.

But the MRGO never did seem worth its ruinous cost and the environmental catastrophe it has wrought. We call it "Mr. Go", but the courtesy hardly seems deserved.

Last week an armada was left idling in the Gulf of Mexico while salvage workers struggled to raise the supply boat, Lee III, lost with all five hands last weekend. A handful of smaller ships did manage to make it under the bridge on the Mr. Go and up to New Orleans, but that is not an option for the Leviathans of the modern deep. They had to wait until the river was clear.

Mr. Go must have seemed like a good idea when it was opened some 40 years ago to provide a short cut from the Port of New Orleans to the Gulf for ocean-going vessels. The journey is 120 miles by river, 76 miles by Mr. Go, which was dug 36 feet deep and 600 feet wide through the marshes of St. Bernard Parish and Chandeleur Sound.

Mr. Go was supposed to provide a major economic boost and stimulate industrial development, but traffic never did meet expectations. On an average day only a couple of ships will pass along it, while dredging costs can easily top $20 million a year. Mr. Go is responsible for only a small percentage of the tonnage coming through the Port of New Orleans.

Still, it does provide a livelihood for 15,000 people, according to the Lake Pontchartrain Basin Foundation, and shippers will resist any plan to close it down until they can find another route from the Gulf to eastern New Orleans. The only way to accomplish that is to build a bigger lock where the Industrial Canal runs into the river, but plans to do so are mired in litigation. Even if that is resolved, the work will take several years.

Although there might be room for debate over Mr. Go's economic impact, there is no disputing its environmental devastation. The Corps of Engineers destroyed 8,000 acres of wetlands to build Mr. Go, which immediately became a conduit for the salt water that drove away the natural wildlife and killed plants that held the marshes together.

Vast stretches of land turned into water, while tides and the wake from large ships eroded the banks of Mr. Go until its width reached 2,000 feet in places.

Now that restoring the coastal wetlands has become a major cause in Louisiana, we are left to rue the ecological follies of yesteryear. Mr. Go has played a major role in bringing us to this pass.

Let us hope a hurricane does not produce a surge along Mr. Go before we have figured out how to close it down. Without the wetlands to absorb its impact, Hurricane Betsy in 1965 came roaring up Mr. Go, flooding homes and killing some 110 people. And that was when Mr. Go had just been dug and was still a slim 600 feet. Next time everyone in sight could float away.

We are certainly taking quite a chance. The Corps of Engineers said the Industrial Canal lock would be completed in 2014, but that was before environmental groups and neighborhood associations filed suit to block it, claiming that toxic materials have been found in the sediment that would have to be dug up.

The plaintiffs want the corps to produce an updated environmental statement to determine whether the lock project can go ahead without poisoning Lake Pontchartrain or the 9th Ward air.

The corps is supposed to be considered the pros and cons of closing Mr. Go Commercial interests say it is vital to maintain access to eastern New Orleans for large cargo ships, while the Coalition to Close the Mississippi River Gulf Outlet maintains that the ecological damage and the risk to public safety are too high a price to pay.

Whenever Mr. Go is closed down, it won't be a minute too soon. If we are lucky, it won't be too late either.