(CNN) -- Much of the central Gulf Coast hunkered down early Wednesday as Hurricane Isaac battered and drenched the region. Authorities warned residents to be prepared for heavy rain, high winds, coastal storm surges and flooding.
Thousands of people in Louisiana, Mississippi and Alabama were under states of emergency. The storm conjures memories of Hurricane Katrina, which slammed the region seven years ago Wednesday and killed nearly 1,800 people.
A summary of the latest preparations and situation in each state:
-- More than half a million customers were without power in Louisiana alone, Entergy and Cleco reported.
-- Tulane University has canceled classes for the rest of the week and will resume on Tuesday after Labor Day, according to the university's website.
-- Gov. Bobby Jindal said the storm is moving slowly, and that will mean long-lasting and powerful winds.
-- He warned of a greater chance of heavy rain, flooding and downed tree limbs and power lines.
-- Tidal surges could occur after storms have passed through areas, the governor said.
-- Entergy officials said they are taking one of their nuclear power plants west of New Orleans offline.
-- State government offices will be closed Wednesday.
-- The new $165 million Seabrook Floodgate at the north end of the Industrial Canal was closed for the first time for a storm event.
-- Forty-one parishes have issued emergency declarations.
-- Seven parishes announced mandatory evacuations in their jurisdictions.
-- Plaquemines Parish officials issued a curfew until to sunrise Wednesday.
-- The Department of Corrections has moved prisoners from coastal parishes to state prison facilities.
-- Flights are being halted out of the New Orleans airport Tuesday and Baton Rouge on Wednesday, authorities said.
-- Bus and street car service in New Orleans and Amtrak and Greyhound service to and from the city have been shut down.
-- President Barack Obama declared a state of emergency, and federal aid is on the way.
-- The Federal Emergency Management Agency is in charge of recovery operations, and more than 4,100 National Guard troops have been activated.
-- The Louisiana National Guard has deployed 48 boat teams and 13 communications teams.
-- New Orleans Mayor Mitch Landrieu did not issue an evacuation order but called for people outside the city's protective levees to leave.
-- The city's pump stations have backup generators ready in case of electrical outages.
-- Crews have been evacuated from oil production platforms and drilling rigs in the Gulf of Mexico.
-- The Coast Guard has closed the Mississippi River from Baton Rouge to the Gulf of Mexico and will not respond to water emergencies until after the storm passes.
-- Cargo terminals within the Port of New Orleans have ceased operations.
-- The Texas A&M-Louisiana Tech football game, originally scheduled for Thursday in Shreveport, has been postponed until October 13.
-- The New Orleans Saints football team moved its practices to Cincinnati.
-- Jindal is skipping the GOP convention in Tampa, Florida, because of the storm.
-- Coast Guard aircrews were searching for a missing person who had been using a personal watercraft off the coast of Pensacola.
-- A tropical storm warning was in effect in parts of western Florida.
-- People were ordered to evacuate parts of downtown Pensacola and some nearby barrier islands.
-- Pensacola International Airport closed at midnight Monday.
-- Okaloosa County officials called for voluntary evacuations of low-lying areas.
-- Isaac caused minor damage as it skirted South Florida.
-- Thousands of homes and businesses remained without power in Miami-Dade County.
-- Thirty members of the Florida National Guard were activated, the governor's office said.
-- Aircraft at six military bases were relocated, the Defense Department said.
-- Because of Isaac, Republicans delayed their national convention in Tampa to Tuesday.
-- All low-lying areas in Hancock County are flooding, according to local emergency management officials
-- There is "quite a bit of flooding" in Pass Christian, Harrison County emergency management said.
-- There are more than 1,160 people without power in Mississippi, according to Entergy.
-- More than 2,100 people are in shelters in the state.
-- Truckloads of water, generators and food were staged and ready for distribution.
-- President Barack Obama declared a state of emergency for southern Mississippi and ordered federal aid.
-- Residents can call 211 for information on shelters, assistance and transportation.
-- Mandatory evacuations have been ordered in parts of Hancock and Jackson counties.
-- Gulfport-Biloxi International Airport has closed.
-- A hurricane warning is in effect for the entire coast.
-- About 1,500 National Guard troops have been deployed.
-- Gulfport authorities ordered the port cleared of cargo vessels.