Hurricane Isaac's winds and rain had left about 290,000 residential and commercial customers in southeast Louisiana without electricity by midnight. The number included customers of Entergy and Cleco.
Entergy reported a total of 279,000 customers had lost power, including about 103,500 in Orleans Parish, 99,500 in Jefferson, 11,500 in St. Bernard, 10,000 in Plaquemines, 15,000 in Lafourche, 11,500 in St. Charles, 6,500 in St. John the Baptist and 8,000 in Terrebonne.
Cleco, which serves customers on the north shore, reported a total of 10,600 power outages, with 9,950 of those in St. Tammany.
Most of the customers that have lost power are likely to remain in the dark throughout the duration of the storm, utility officials say, because crews will not go out to start repairs until winds drop below 30 or 35 mph, which is likely to be Thursday at the earliest.