(Reuters) - Tropical Storm Isaac swirled into the Gulf of Mexico on Monday, disrupting U.S. offshore energy production and threatening to hit Louisiana as a hurricane seven years to the day after devastating Hurricane Katrina.
The storm swiped south Florida on Sunday before moving into warm Gulf waters, where it is expected to strengthen into at least a Category 1 hurricane.
On its current track, Isaac was due to slam into the Gulf Coast anywhere between Florida and Louisiana by midweek, the U.S. National Hurricane Center said.
The governors of Alabama, Louisiana and Mississippi declared states of emergency as a hurricane warning went into effect for the northern Gulf Coast from Louisiana to the Florida Panhandle.
It included New Orleans, devastated when Hurricane Katrina swept over the city on August 29, 2005, killing more than 1,800 people and causing billions of dollars of damage along the coast.
"It is difficult to realize that to the day - seven years after Katrina - another hurricane is headed our way," Mississippi Governor Phil Bryant said.
Early Monday morning, Isaac was about 405 miles southeast of the mouth of the Mississippi River with top sustained winds of 65 mph and moving west-northwest at 14 mph.
It was expected to be centered over the Gulf Coast late Tuesday night or early on Wednesday. Evacuation orders for some low-lying parts of the Gulf Coast already were in effect Monday morning.
Energy producers in the Gulf worked to shut down some of their operations ahead of what could be the biggest test for U.S. energy installations since 2008, when Hurricanes Gustav and Ike disrupted offshore oil output for months and damaged onshore natural gas processing plants, pipelines and some refineries.