The last time I saw Cairo, Ill., it was dry and in despair. My trip was to cover the closing of the old river town's only hospital. Some said it was a sign of impending oblivion, like the lights going out on the foundering Titanic.

Bank president D.L. Gustafson told me then that he hoped for better days ahead, predicting the population of 5,000 might even grow 50 percent in the next decade.

That was 24 years ago, and those better days proved elusive. The population did not grow by half, it fell by almost half. And early this week, it appeared that Cairo's cause of death might turn out to be the same as the Titanic's — drowning.

Water was always as great a threat to Cairo, at the confluence of the Mississippi and Ohio rivers, as to a ship at sea. The townspeople depend upon a levee as surely as sailors depend upon a hull.

When it appeared that Cairo's levee might yield to a high river level, a decades-long man versus nature fight turned into man versus man.

The U.S. Army Corps of Engineers, overseer of the flood control system, chose to save Cairo, with its 2,800 residents at the southern tip of Illinois, by blowing up an opposing levee downstream. Tuesday night's explosions sacrificed about 132,000 acres of Missouri farmland and imperiled up to 300 homes.

Missouri sued to block the move but failed. Its House speaker, Steve Tilley, even used some unkind words about the condition of Cairo, for which he later apologized. You can understand how he might get carried away for his own constituency.

There is no disputing that Cairo is a ramshackle shadow of its riverboat-era heyday. Industries went the way of the hospital. Many of the people left behind are profoundly poor. In the 2000 census, its school district had Illinois' highest proportion of students in poverty: 60 percent.

My own view, briefly held, was to wonder why the corps didn't just wait and let nature take its course. May the stronger levee win. With luck, it might end up win-win.

But then I realized that people had removed nature from the equation decades ago, by building the levees in the first place. Nature's plan, which flooded those areas occasionally for eons, was too inconvenient. With the audacity to make changes came responsibility for managing the consequences.

Didn't those farmers have good reason to depend upon their levee? They're suing the corps over it. But then, Cairo was a city long before that levee was built. Does seniority count? Maybe it was as simple as comparing 100 homes on the west to perhaps 700 on the east.

We've seen emergency breaches of levees before.

In 1993, a natural break in a Mississippi River levee flooded Valmeyer. The torrent that swept southward across the bottoms seemed sure to overpower a fragile lateral levee protecting the town of Prairie Du Rocher. So engineers deliberately broke a Mississippi River levee in between, filling thousands of acres and up to 100 homes with a pool intended to absorb the impact. It worked. But the circumstances were different: the sacrificed land was doomed to flood hours later anyway.

Levee integrity is serious enough business that a man was sentenced to five years in prison for property damage after running his johnboat — he claimed recklessly, not deliberately — into a sandbag-reinforced levee that same year, hastening the flooding of West Alton.

More serious still was the case of James R. Scott, convicted of sabotaging a Missouri levee opposite Quincy, Ill., also in '93. Officials claimed that Scott, with a record of arson and burglary, wanted to strand his wife on the far side to leave him free to party. The result inundated 14,000 acres, damaged scores of buildings and closed the only bridge along a 200-mile stretch of the Mississippi River for 71 days.

Now, almost 18 years later, Scott remains in a Missouri prison, serving a life term for a crime that carries what has to be the grandest title in all jurisprudence: causing a catastrophe.

Nobody is prosecuting the Corps of Engineers. It was not reckless, nor was its motive silly or personal. But what an awful decision it must have been to decide whether to cause a catastrophe — and then to choose which catastrophe to cause.