THIS IS NOT an easy book to read, which is not to say that it lacks merit. The dispatches collected from The Nation’s coverage of Hurricane Katrina chronicle a disaster that could have been avoided, if local, state, and federal authorities had upheld their responsibilities to protect the citizenry and the land on which they live. There is no more enduring emblem of the decline in American leadership than the photograph of President George W. Bush viewing the damage to New Orleans from the window of Air Force One. This image seems to hover around this book, like a ghostly presence in which we find the just measure of our political, cultural, and societal failure.

To read “Unnatural Disaster” is to relive those days and weeks in which the world watched, amazed, as the last superpower proved unable or unwilling to save its own citizens from the rising waters. Here are portraits of the victims, rescuers, and harried officials — a girl in a temporary shelter who receives massages from visiting Scientologists, members of the Cajun Navy who took their own boats into the streets to bring people to safety — the individuals, that is, at the heart of this tragedy.

How to explain it? “Racism and incompetence,” Christian Parenti writes, “seemed to merge to create a sluggish response.” It’s a lethal combination, to which must be added the near certainty that, as Mark Hertsgaard argues, with global warming this is a sign of things to come. No wonder Katrina haunts our imagination, if not our body politic.

It is no surprise that some of the work is dated, nor that repetitions abound. What is surprising is how much holds up: an essay on the prisoners forgotten in New Orleans, a call for a new New Deal, questions about the state of our democracy. The coverage drops off, predictably, after a few months, and one longs for more of the sustained media attention of last year. But this is old news: a bleak story, which should nevertheless be required reading for every American.