Plaquemines Parish crews hustled to the levees that protect the low-lying New Orleans suburb and St. Charles Parish closed schools through Wednesday as Tropical Storm Isaac's path moved west.
It's expected to become a Category 2 hurricane before making landfall somewhere from east of Morgan City to the Florida Panhandle.
Plaquemines, Jefferson and St. Charles parishes all have declared a state of emergency. St. Charles Parish is stocking all sandbag locations; people will need to bring their own shovels to fill bags.
The captain of the port of Morgan City warned that gale-force winds are expected within 72 hours.
The New Orleans Fair Grounds Race Track ordered evacuation about 700 horses from its stables.