Hurricane Sally Is a Slow-Moving Threat. Climate Change Might Be Why.

In the oyster and fishing town of Bayou La Batre, how Mr. Nelson found himself under a house, and how the house got built in the first place, was tangled in the long, painful drama of a changing climate that has irrevocably complicated life along the Gulf Coast.

Mr. Nelson, 66, had been living more than 300 miles west of Bayou La Batre, in the small Louisiana town of Hackberry. But a few weeks ago, Hurricane Laura roared out of the Gulf and devastated Hackberry, including Mr. Nelson’s home, a little travel trailer right on the water.

“You’re looking at the last person to get out of Hackberry,” said Mr. Nelson, who made his escape just before Laura’s landfall, when his sister Stephenie Bosarge, 63, picked him up and brought him to her elevated home just off the water on the Alabama shore.

A different house had been on the property before Hurricane Katrina blew it away in 2005, along with Ms. Bosarge’s wedding bands, family photos and oyster shop. The Volunteers of America came through town and built her this new raised house a few blocks from the water.

Since Katrina, many houses in Bayou La Batre are now jacked up on stilts, and people have their ways of figuring out what to do with all that space below, parking a truck or boat, stashing junk or storing tools. At her house, Ms. Bosarge installed a tiki bar, some porch swings and a stereo system.

Soon, they planned on evacuating, riding out the storm with a relative on higher ground in Grand Bay. But for the time being, the siblings sat on their porch swings, watching this new slow-moving disaster unfold around them, wondering how high the water would rise and joking about Mr. Nelson’s bad fortune.

But they were serious about what had happened to their way of life, and the life of so many other Gulf people. “It is coming to an end,” Ms. Bosarge said. “Baby, I knew that years ago.”

Richard Fausset reported from Bayou La Batre, Rick Rojas from Atlanta, and Henry Fountain from Albuquerque. Mike Baker contributed reporting from Seattle, Simon Romero from Albuquerque, and Maria Cramer from New York.