Florida Gov. Rick Scott briefs the press on his state's Irma response.
Irma left a stunning 13 million Florida residents without electricity - two-thirds of the state's residents - after recently sweeping across it as a Category 4 hurricane.
The storm also caused record flooding in the Jacksonville area, forcing dozens of rescues there on Monday as it headed inland to Georgia and South Carolina.
School was cancelled in multiple communities across Georgia Tuesday, and more than 1.2 million customers there lacked power as of that morning.
Many South Carolina schools were additionally closed or operating on a delayed scheduled early Tuesday, and more than 220,000 customers were without electricity there that morning.
Irma has since weakened to a tropical depression, and the storm's remains were were blowing through Alabama and Mississippi early Tuesday after drenching Georgia.
The Associated Press contributed to this report.
Officials say Hurricane Irma has been blamed for more than 40 deaths, including six in Florida.
On Monday a Florida man was apparently electrocuted by a downed power line. Winter Park police said the found 51-year-old Brian Buwalda lying in the roadway after receiving multiple calls. A medical examiner will determine whether the official cause of death, but officials said it appeared to be a weather-related accident.
Georgia officials confirmed two people have died as a result of Tropical Storm Irma.
Georgia Emergency Management Agency spokeswoman Catherine Howden said the second death occurred in Sandy Springs, which is north of Atlanta.
The storm is also being blamed for the death of a 62-year-old man in southwest Georgia.
Authorities said the man used a ladder to climb onto a shed Monday when winds in the area had exceeded 40 mph. Worth County sheriff's spokeswoman Kannetha Clem said the man's wife called 911, saying the victim had a heart attack.
Florida Gov. Rick Scott held a press conference Monday after surveying the damage Hurricane Irma left behind on the Florida Keys.
"My heart goes out to the Keys," Scott said. "There's devastation ... it's horrible what we saw."
Scott said there is "devastation" there and he hopes everyone who stayed behind survived the storm. The governor added that every mobile home park in the Keys had overturned homes.
Likewise, President Donald Trump's National Security adviser Tom Bossert said it could take weeks before evacuees can return to their homes.
A Flash Flood Emergency has been issued for parts of Charleston County, South Carolina.
A tornado watch is in effect for parts of Georgia and South Carolina until 10 p.m. Tuesday.
Our affiliate WPDE shared video after wind blew the roof off the Garden City Inn in Garden City, South Carolina.
Tropical Storm Irma continues to weaken as its center moves into southern Georgia, the National Hurricane Center (NHC) said Monday.
Irma's maximum sustained winds have decreased to near 60 mph, with higher gusts.
The storm is centered about 50 miles south-southeast of Albany, Georgia, and about 55 miles east of Tallahassee, Florida.
Irma is moving north-northwest at 17 mph, the NHC said. It will continue to move over southwestern Georgia on Monday and will move into eastern Alabama on Tuesday morning.
The National Weather Service (NWS) put most of eastern Alabama under a tropical storm warning Monday, and the rest of the state was placed under a wind advisory.
Strong winds and gusts of up to 50 mph were expected through early Tuesday, the Alabama Emergency Management Agency said.
Hotels in Alabama filled with evacuees from Florida on Monday, with Irma's center expected to cross into Georgia on Monday afternoon. Schools and businesses across Alabama were closed.
Nearly 7.2 millions homes and businesses in multiple states -- most of them in Florida -- are without power.
A Flash Flood Emergency is underway in downtown Jacksonville, Florida, and the National Weather Service (NWS) warned that waters will continue to rise there until around 2 p.m. Monday.
Water levels could reach four to six feet above ground level on the immediate banks of the St. Johns River as the tide moves southward through the St. Johns River basin, the NWS said.
"This is a PARTICULARLY DANGEROUS SITUATION," the NWS said. "Go to the highest point in your house if a single story, or on the second story if possible."
The NWS also warned people not to go into flood waters "as there may be an electric current in the water."
Here's aerial footage of Irma's damage in Florida.
More than 6.2 million homes and businesses in Florida are without power Monday, and officials warned that it could be weeks before power is restored for everyone.
About 220,000 people are in shelters.
Power outages from Tropical Storm Irma aren't limited to the Sunshine State. More than 100,000 customers in Georgia and more than 80,000 in South Carolina are without power Monday.
Our affiliate WCIV shared this video of a waterspout off Isle of Palms in South Carolina.
Authorities conducted a dramatic rescue on Edisto Beach in South Carolina, our affiliate WCIV reported.
Waves from Tropical Storm Irma hit the Battery in downtown Charleston, South Carolina.
Fort Lauderdale, Florida, police said officers have arrested 19 people for "burglarizing businesses & residences" during Hurricane Irma.
Miami-Dade police have arrested 28 people for burglary and looting, our affiliate WPEC reported.
Here are some images of flooding in downtown Jacksonville.
Tropical Storm Irma is "gradually weakening" as it moves over northern Florida, the National Hurricane Center (NHC) said Monday morning.
Irma's maximum sustained winds have decreased to 65 mph, with higher gusts, and the storm is likely to become a tropical depression on Tuesday.
The storm is centered about 70 miles east of Tallahassee and about 85 miles north of Cedar Key, and it is moving north-northwest at 17 mph.
Irma's center will move into southwestern Georgia later Monday, then move into eastern Alabama on Tuesday morning, the NHC said.
Crews rescued had 46 people from flooded homes south of Jacksonville, Florida, by early Monday.
John Ward, emergency operations manager for Clay County, said an "undetermined number" of people were stranded as Tropical Storm Irma's winds and rain brought record flooding to the area's creeks and ponds, but no injuries or deaths had been reported.
Irma's effects were also being felt in Savannah, Georgia, on Monday morning, with winds and heavy rain in the area. Irma is forecast to cross into Georgia on Monday afternoon.
The National Weather Service warned that swollen rivers, streams and creeks in Georgia were at risk of overflowing, though the threat of storm surge had decreased along Georgia's coast.
Irma's effects are felt at Charleston harbor in South Carolina.
Irma has weakened to a tropical storm but is still producing some wind gusts to near hurricane force, the National Hurricane Center (NHC) said Monday morning.
Irma's maximum sustained winds have decreased to near 70 mph, with higher gusts.
"Additional slow weakening is forecast, and Irma is expected to weaken to a tropical depression by Tuesday afternoon," the NHC said.
Irma has a "very large wind field," the NHC noted. Hurricane-force winds extend outward up to 60 miles from its center, mainly to the west of its center, and tropical storm-force winds extend outward up to 415 miles.
Irma is centered about 30 miles north-northeast of Cedar Key, Florida, and about 105 miles north-northwest of Tampa. It is moving north-northwest at 18 mph.
"The center of Irma will move near the northwestern coast of the Florida Peninsula this morning, cross the eastern Florida Panhandle into southern Georgia this afternoon, and move through southwestern Georgia and eastern Alabama tonight and Tuesday," the NHC said.
The National Weather Service (NWS) has issued a Flash Flood Emergency for areas of downtown Jacksonville, Florida, near the St. Johns River, warning that flash flooding is expected to begin shortly.
"This is a PARTICULARLY DANGEROUS SITUATION!" the NWS warned. "Water is expected to rise another 1 to 2 feet when winds switch to the south and push water northward into downtown... and the high tide begins to come into the river!"
In addition to downtown Jacksonville, San Marco, Landon Park, South Hampton and Riverdale will experience flooding, the NWS said.
The NWS urged residents not to attempt to move through flood waters and to seek shelter in a "second story or higher portion of your structure."
"Swiftly rising water could sweep you away," the NWS warned.
Residents were urged not to attempt to travel unless they are "fleeing an area subject to flooding or under an evacuation order."
"Move to higher ground now," the NWS warned. "This is an extremely dangerous and life-threatening situation."
Hurricane Irma has left more than 3.3 million businesses and homes across Florida without power as of Monday.
Utility officials said that morning that it will take weeks to restore electricity to those impacted by the powerful storm.
Irma continued moving north along Florida’s western coast Monday, while the hurricane’s outer bands pushed into Georgia.
The storm’s center was roughly 60 miles north of Tampa that morning, but in a much-weaker state than when Irma initially struck Florida.
Irma on Sunday arrived in Florida as a Category 4 hurricane, but it is now a Category 1 storm with winds of 75 mph.
The National Hurricane Center (NHC) on Monday said that “additional weakening is forecast” for the storm.
“Irma is expected to weaken to a tropical storm this morning and to a tropical depression by Tuesday afternoon,” it said in an advisory.
The NHC cautioned, however, that Irma would remain a credible threat to areas it troubles Monday.
“There is the danger of life-threatening storm surge flooding along portions of the coasts of Florida, Georgia and South Carolina, where a Storm Surge Warning remains in effect,” it said.
Flash flood warnings are in effect for Jacksonville and several other Florida cities.
Storm surge flooding has already exceeded the all-time record in downtown Jacksonville.
“Irma will continue to bring life-threatening wind impacts to much of central and north Florida, with hurricane-force winds near the center,” the NHC added.
“Wind hazards from Irma will continue to spread northward through Georgia and into portions of Alabama, Tennessee, South Carolina, and North Carolina.”
The NHC additionally tweeted out its latest rainfall forecast graphic for Irma, which has resulted in more than 160,000 people waiting the storm out in shelters across Florida.
Nearly 7 million people in the Southeast U.S. were warned to shelter from Irma as the storm approached, including 6.4 million in Florida alone.
Irma was the most powerful Atlantic Ocean hurricane ever recorded during its peak last week, boasting a top wind speed of 185 mph.
The Associated Press contributed to this report.