More than 1.5 million people are still without power as Matthew on Sunday brought Hurricane-force wind gusts and flooding to the outer banks of North Carolina, where the storm left at least seven dead.

Almost 423,000 homes and businesses were still in the dark in Florida, and more than 1.1 million had lost power in Georgia and North and South Carolina, as of noon New York time. Duke Energy Corp. said it will need to rebuild sections of its electrical systems in the states after heavy damage. Matthew has been downgraded from a hurricane to a post-tropical cyclone, and no further damage is expected as it moves east away from the coast.

Top winds of 75 miles (121 kilometers) per hour are expected to dwindle to between 30 and 40 mph by the afternoon as Matthew pulls farther away from the coast, allowing fuel terminals and pipelines to start returning to service. The storm will gradually weaken as it is absorbed within a frontal boundary Monday night, according to a U.S. National Hurricane Center advisory. On Saturday, Matthew made landfall in South Carolina. The death toll in the U.S. reached at least 16, after the storm earlier lay waste to Haiti, where it left hundreds dead.

Matthew roiled markets for everything from natural gas to orange juice as traders bet on the extent of supply disruptions. Gas futures rallied to the most in 21 months Friday on speculation that limited outages would keep demand for the power-plant fuel high.

For some Duke service areas, the electrical system will need to be rebuilt after Matthew “left large portions of the Carolinas more heavily damaged than projected,” the company said in a statement Sunday. The company is reporting 660,000 outages in the region and estimates it could take as much as a week to complete restorations.

Tyson Foods Inc. had to shut a plant in Jacksonville, Florida, as Matthew neared the coastline, and Kinder Morgan Inc. closed terminals, pipelines and a liquefied natural gas terminal near Savannah, Georgia.

Twelve U.S. power generators, including two nuclear plants, were in the storm’s path, according to data compiled by Bloomberg. NextEra Energy Inc.’s nuclear reactor at the St. Lucie complex in Florida remained closed on Sunday, according to company spokesperson Bud Fraga, who declined to provide a date for its restart.

Cotton and peanut crops were most at risk from heavy rains, David Streit, senior lead forecaster at Bethesda, Maryland-based Commodity Weather Group LLC said Friday. The extent of damage to Florida’s oranges and grapefruit “may not be known for days,” said Shannon Shepp, executive director of Florida’s Department of Citrus, on Friday.