In Plaquemines Parish, Luke Petrovich, the parish president, said 13,000 to 15,000 people evacuated.

The charter provided for the election of a parish president, essentially a parish-wide mayor.

"This is blackmail; you can't tell me it's not," said Henry Rodriguez, the parish president.

"We had 48,000 families that needed new refrigerators," said Kevin Davis, the parish president, whose offices are in this city in the center of the parish.

The parish president, Dale Hymel Jr., who favors the Shintech plant, said it would help alleviate poverty.

The incumbent parish president, Democrat Benny Rousselle, also a former state representative, was term-limited.

In nearby St. Bernard Parish, 120 municipal employees have already lost their jobs and the parish president is begging for federal assistance to make payroll.

To Mr. Rodriguez, the parish president, the top question is how to give residents a sense that their safety comes first.

Aaron Broussard, the parish president, issued the following statement, which was posted on the parish's website:

"He's been very nice and very knowledgeable and knows the inner workings of government," said Charlie Reppel, the chief of staff to the parish president.