Almost 800 rescued in St. John the Baptist Parish after Hurricane Ida
At least three people have died as a result of the storm.
Ida is barreling through Louisiana after making landfall in the state as a powerful Category 4 hurricane on Sunday afternoon.
It was one of the strongest hurricanes on record -- by both wind speed and pressure -- to roar ashore in Louisiana.
Ida, now a tropical storm, is hitting on the 16-year anniversary of Katrina, a Category 3 hurricane that ravaged the Gulf Coast. Hurricane Katrina unleashed a series of events, taking the lives of more than 1,800 people and leaving more than $100 billion worth of damage in its wake.
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Flash flood warning in effect in New Orleans
As of 6 p.m. ET, Category 4 Hurricane Ida was moving northwest near Houma, Louisiana.
Sunday night's forecast calls for heavy rain, high wind gusts, dangerous storm surge and possibly tornadoes and flash flooding.
A flash flood warning has been issued in New Orleans where 1 to 3 inches of rain is already on the ground with another 4 to 8 inches expected.
An extreme wind warning is in effect in parts of southeastern Louisiana extending to areas just southwest of New Orleans. Wind gusts up to 125 mph are possible Sunday night in St. John the Baptist, St. James, St. Charles, Terrebonne, Lafourche and Jefferson parishes.
-ABC News' Melissa Griffin
Over 15,000 people in shelters in Louisiana
First responders will likely not be able to respond to calls in Louisiana until daybreak Monday, Gov. John Bel Edwards warned.
"I have no doubt we're going to see extreme devastation in Grand Isle and elsewhere," he said.
Over 15,000 people are in shelters across the state, the governor said.
Sixty-one intermediate care facilities, 22 nursing homes and 18 assisted living facilities have been evacuated, but no "tier one" hospitals have had to be evacuated, he said.
At least 442,925 customers in Louisiana are without power as of 5 p.m. ET.
Edwards said his biggest concern is outages because of how many people are in hospitals. "I understand that generators are great, but over time they tend to fail," he said.
-ABC News' Will McDuffie
Ida's latest forecast
Category 4 Hurricane Ida, moving northwest at 11 mph, is slamming Louisiana with powerful winds, torrential rain and dangerous storm surge.
When measuring wind speed, Ida is one of the three most powerful hurricanes to strike Louisiana. Along with Ida, Laura in 2020 and the Last Island hurricane in 1856 also all clocked in at 150 mph.
A tornado watch is in effect in parts of Louisiana, Mississippi, Alabama and Florida, and storm surge could top 8 feet along the Louisiana and Mississippi coast.
Ida will weaken through the night but will remain a dangerous hurricane, bringing rounds of very heavy rain and possibly flash flooding to the New Orleans area.
Louisiana and Mississippi could see 10 to 20 inches of rain in some areas.
The heavy rain and possible flash flooding will move inland Monday and Tuesday. Waverly, Tennessee, which was hit with deadly, catastrophic flooding last weekend, could see another 2 to 5 inches of rain late Monday into Tuesday.
-ABC News' Dan Peck
Storm damage 'every bit as bad as Katrina': Louisiana lieutenant governor
Louisiana Lt. Gov. Billy Nunguesser spoke with ABC News about the damage to the state and said it looked like it was going to be rough for the southern end.
“I believe it’s gonna be every bit as bad as Katrina," he told ABC News.
Nunguesser said flooding is already cataclysmic, and the levees near Myrtle Grove and other places were either breached or topped by water.
The lieutenant governor said he was especially concerned about Plaquemines Parish, which has oil and gas related infrastructure.
Nunguesser said he has heard reports of a giant floating platform on which oil workers live coming unmoored and floating somewhere in Barataria Bay.
-ABC News' Matt Gutman
3rd storm-related death confirmed
Deano Bonano, a councilman for District 2 in Jefferson Parish, told ABC News that there has been one confirmed fatality in his parish from Hurricane Ida.
Details about the death and the identity of the victim weren't immediately available.
-ABC News' Darren Reynolds