Authorities say at least seven people have been killed after a “superfog” of smoke from south Louisiana marsh fires and dense fog caused multiple massive car crashes involving 158 vehicles.

Rescuers in boats, helicopters and high-water trucks brought hundreds of people trapped by Hurricane Ida's floodwaters to safety Monday and utility repair crews rushed in, after the furious storm swamped the Louisiana coast and ravaged the electrical grid in the stifling, late-summer heat.

For the community of Jean Lafitte, the question is less whether it will succumb to the sea than when — and how much the public should invest in artificially extending its life.

A relentless heat dome that has parked over the Gulf Coast region for much of summer reached a climax late last week and this weekend, bringing some of the highest temperatures ever recorded from coastal Texas to southern Alabama. The water has also heated up far beneath the surface. In fact, temperatures of nearly 88 degrees are common to depths of 165 feet below the surface, according to data posted to Twitter by Kim Wood, a professor of meteorology at Mississippi State University. University of Miami hurricane scientist Andy Hazelton called the ocean heat “other-worldly.”