Hurricane Nate came ashore at a sparsely populated area at the mouth of the Mississippi River last night, pelting the central Gulf Coast with wind and rain.
The fast-moving storm is headed toward the Mississippi coast, where it was expected to make another landfall and threatened to inundate homes and businesses.
Nate was expected to pass to the east of New Orleans, sparing the city its most ferocious winds and storm surge.
And its quick speed lessened the likelihood of prolonged rain that would tax the city's weakened drainage pump system.
The city famous for all-night partying was placed under a curfew, effective at 7pm, but the mayor lifted it when it appeared the storm would pass by and cause little problems for the city.
Still, the streets were not nearly as crowded as they typically are on a Saturday night and Mayor Mitch Landrieu asked people to shelter in place.
Cities along the Mississippi coast such as Gulfport and Biloxi were on high alert. Some beachfront hotels and casinos were evacuated, and rain began falling on the region yesterday. Forecasters called for three to six inches (seven to 15cm) with as much as 10 inches (25cm) in some isolated places.
Nate weakened slightly and was a Category One storm with maximum winds of 85 mph when it made landfall in a sparsely populated area of Plaquemines Parish.
Forecasters had said it was possible that it could strengthen to a Category Two, but that seemed less likely as the night wore on.
Storm surge threatened low-lying communities in southeast Louisiana, eastward to the Alabama fishing village of Bayou la Batre.
Governors in Louisiana, Mississippi and Alabama declared states of emergency. The three states have been mostly spared during this hectic hurricane season.
"This is the worst hurricane that has impacted Mississippi since Hurricane Katrina," Mississippi Emergency Management Director Lee Smithson said yesterday. "Everyone needs to understand that, that this is a significantly dangerous situation."
Officials rescued five people from two sailboats in choppy waters before the storm. One 41-foot sailboat lost its engine in Lake Pontchartrain and two sailors were saved. Another boat hit rocks in the Mississippi Sound and three people had to be plucked from the water.
Louisiana Gov. John Bel Edwards urged residents to make final preparations quickly and stressed that Nate will bring the possibility of storm surge reaching up to 11 feet in some coastal areas.
"It's going to hit and move through our area at a relatively fast rate, limiting the amount of time it's going to drop rain," Edwards said. "But this is a very dangerous storm nonetheless."
Streets in low-lying areas of Louisiana were already flooded. Places outside of levee protections were under mandatory evacuation orders and shelters opened there.
Some people worried about New Orleans' pumping system, which had problems during a heavy thunderstorm on Aug. 5. The deluge exposed system weaknesses - including the failure of some pumps and power-generating turbines - and caused homes and businesses to flood. Repairs have been made but the system remained below maximum pumping capacity.
Meanwhile Florida Gov. Rick Scott warned residents of the Panhandle to prepare for Nate's impact.
"Hurricane Nate is expected to bring life-threatening storm surges, strong winds and tornadoes that could reach across the Panhandle," Scott said. The evacuations affect roughly 100,000 residents in the western Panhandle.
Nate killed at least 21 people after strafing Central America.