On a misty November morning in 2005, I was photographing in New Orleans’ Ninth Ward neighborhood a few blocks from where one of the levees had failed 10 weeks earlier. Squatting in a driveway in foul-smelling mud, adjusting the knobs on my camera, I stood up to stretch my back and noticed a man sitting on some concrete steps a few houses away.

He was the only other person I had seen for several hours; the otherwise empty streets were as still and silent as those of a ghost town. I felt I ought to acknowledge him before returning under my dark cloth, so I left my camera and crossed the street. As I approached I saw he was elderly, a tall slender black man with a pointed chin and lean, skeleton-like arms and hands.

I asked if this was his neighborhood. He told me his great-grandfather had built this house in the 1890s; his grandfather was born and died in this house, his father was born and died in this house, “and 76 years ago I was born in this house.” He pointed behind him to where the front door should have been. The entire house and everything in it was gone, swept away and smashed together with uprooted trees and cars and the remains of other houses in a huge splintered pile of rubble a quarter mile away. There was nothing left but the heavy cement steps, and some cinder blocks and grimy debris.

“They’re paying for me to stay in a motel room in Kansas City,” he told me. “It stinks of smoke and I don’t know anyone. I lost my wife a couple of years ago.” He pointed down the block to a small white building that was pushed off its foundation into the middle of the street. It was still standing, but twisted sideways with its back torn open. “That’s my church. The people are all gone. There used to be people …” His voice stopped as he gestured at the ruined landscape.

After a pause I asked him what he was going to do. “Same thing I’ve always done,” he said. “Sit on my front steps. I don’t belong anywhere else. I’m not going to rot away in some motel. This is where I am from, and this is what I do — I sit on my front steps — so here I am sitting on my front steps.”

Almost 300,000 Americans lost everything they owned to Katrina. There is evidence to suggest that this disaster may not have been an entirely natural event like an earthquake or tsunami. The hurricane’s severity can be linked to global warming, which is at least partially a human-caused phenomenon. Our individual consumer practices affect the environment in increments that cannot be measured, yet our Gulf Coast residents experienced Katrina directly and catastrophically. The question is whether we are all accountable to some degree.