Sean Gardner / Reuters
HESCO employees work at closing off Highway 23 South as Tropical Storm Isaac heads towards the Louisiana coast line in Oakville, Louisiana, Aug. 28. Tropical Storm Isaac was near hurricane force as it bore down on the U.S. Gulf Coast on Tuesday and was expected to make landfall in the New Orleans area seven years after it was devastated by Hurricane Katrina.
David J. Phillip / AP
Gus Williams, left, feeds his step-granddaughter Somaya Washington, right, as her mother, Areonisha Washington, center, watches after evacuating to a shelter in Houma, La., Tuesday, on May 28. Forecasters at the National Hurricane Center warned that Isaac, especially if it strikes at high tide, could cause storm surges of up to 12 feet (3.6 meters) along the coasts of southeast Louisiana and Mississippi and up to 6 feet (1.8 meters) as far away as the Florida Panhandle.
Chris Graythen / Getty Images
Bourbon street remains virtually empty ahead of Tropical Storm Isaac on August 27, in New Orleans, Louisiana. Tropical Storm Isaac is expected to strengthen into at least a Category 1 hurricane before making landfall near Louisiana.
Jonathan Bachman / Reuters
New Orleans resident Diana Whipple stands on the shore of Lake Pontchartrain as Tropical Storm Isaac approaches New Orleans, Louisiana, Aug. 28. Tropical Storm Isaac was near hurricane force as it bore down on the U.S. Gulf Coast on Tuesday and was expected to make landfall in the New Orleans area seven years after it was devastated by Hurricane Katrina.
Alan Diaz / AP
Tropical Storm Isaac drenches multiple countries as it moves toward Louisiana.
By Miguel Llanos, NBC News - A slow-moving giant of a system, Tropical Storm Isaac early Tuesday was making its way toward landfall, most likely as a Category 1 hurricane, along the Louisiana or Mississippi coast Tuesday night or early Wednesday.
President Barack Obama added his voice to those of local officials urging residents to hunker down or evacuate if told to do so. "Now's not the time to tempt fate," he said in brief comments. "Listen to your local officials and follow their directions, including if they tell you to evacuate."
Isaac has 70 mph sustained winds, four miles below hurricane strength. "The wind hasn't quite gotten there yet," National Hurricane Center Director Rick Knabb said of its strength. Click here to continue reading this story.