The waters are receding in Houston, and so, inevitably, is national interest. But Harvey will leave a huge amount of wreckage behind, some of it invisible. In particular, we don’t yet know just how much poison has been released by flooding of chemical plants, waste dumps, and more. But it’s a good bet that more people will eventually die from the toxins Harvey leaves behind than were killed during the storm itself.

Oh, and if you trust the current administration to handle Harvey’s aftermath right, I’ve got a degree from Trump University you might want to buy. There are already signs of dereliction: Many toxic waste sites are flooded, but the Environmental Protection Agency is conspicuously absent.

Anyway, Harvey was an epic disaster. And it was a disaster brought on, in large part, by bad policy. As many have pointed out, what made Houston so vulnerable to flooding was rampant, unregulated development. Put it this way: Greater Houston still has less than a third as many people as greater New York, but it covers roughly the same area, and probably has a smaller percentage of land that hasn’t been paved or built on.

Houston’s sprawl gave the city terrible traffic and an outsized pollution footprint even before the hurricane. When the rains came, the vast paved-over area meant that rising waters had nowhere to go.