A FEW THINGS to get straight about Hurricane Katrina:

God wasn't angry at New Orleans. (Who do you think makes breasts?) Nor, my atheist friends, did Mother Nature turn capriciously against the place, socking it with a storm the likes of which we'll never see again. And, with apologies to Kanye, even if George W. Bush fucking loved black people, what happened to the town in August 2005 would have been just as awful.

In his painstakingly researched documentary The Big Uneasy—surprisingly accessible given the dizzying array of charts, maps, and jargon used to make its case—satirist and Simpsons voice actor Harry Shearer punctures the myth that Katrina's ravaging of a vibrant city was an unforeseeable, unpreventable natural calamity. Taking aim at decades of incompetence by the US Army Corps of Engineers—if not outright malfeasance—Shearer enlists a cast of scientists and journalists to explain how shoddy levees, bad science, government-sponsored coastal erosion, and the averted eyes of politicians all conspired to do what nature never could've done on its own.

Even more alarming, the whole thing could happen again—in New Orleans or any other city where shaky walls allegedly are keeping water at bay. The Army Corps of Engineers has refused to reckon its role in the disaster or change its ways.

Meanwhile, reports and findings that question the myth are stepped on, and whistleblowers and dissenting scientists—like the ones who appear in The Big Uneasy—are either pilloried or punished.

One warning: Shearer occasionally drifts into the maudlin. In an attempt to also tell the mostly untold story of New Orleans' rebirth, he cuts to a panel of boosterish, vaguely sentimental intellectuals he's convened to emptily discuss the city's progress. The Big Uneasy is a long documentary—98 minutes—and with all that talk about water, you might want to seize this chance to take a mid-screening piss.