ATLANTA (AP) -- Irma weakened to a still-deadly tropical storm as it swirled beyond Florida, killing at least three people in Georgia, flooding the coast, sending trees crashing onto homes and forcing the world's busiest airport in Atlanta to cancel hundreds of flights.
The former hurricane remained an immense, 415-mile (668-kilometer) wide storm as its center moved on from Florida Monday afternoon, giving its still-formidable gusts and drenching rains a far reach.
Some 540,000 people were ordered to evacuate days earlier from Savannah and the rest of Georgia's coast. Irma sent 4 feet of ocean water into downtown Charleston, South Carolina, as the storm's center passed 250 miles (400 kilometers) away. City officials urged residents to stay off the streets.
In Atlanta, people nervously watched towering oak trees as the city, 250 miles inland, experienced its first tropical storm warning.
The body of a 62-year-old man who climbed a ladder behind his home was found under debris on the roof of his shed in southwest Georgia, where winds topped 40 mph (65 kph), Worth County sheriff's spokeswoman Kannetha Clem said. His wife had called 911 saying he'd had a heart attack.
"He was lodged between two beams and had a little bit of debris on top of him," Clem said. "He was on the roof at the height of the storm."
Another man, in his 50s, was killed just outside Atlanta when a tree fell on his house, Sandy Springs police Sgt. Sam Worsham said.
And a woman died when a tree fell on a vehicle in a private driveway, according to the website of the Forsyth County Sheriff's Office.
Charles Saxon, 57, became South Carolina's first recorded death when he was struck by a tree limb while clearing debris outside his home in Calhoun Falls amid wind gusts of about 40 mph, according to a statement from Abbeville County Coroner Ronnie Ashley.
Communities along Georgia's coast were swamped by storm surge and rainfall arriving at high tide Monday afternoon. On Tybee Island east of Savannah, Holland Zellers was grabbing a kayak to reach his mother in a home near the beach.
"In the street right now, the water is knee-to-waist deep," Zeller said.
Tybee Island City Manager Shawn Gillen said waters were receding quickly, but many of the 3,000 residents' homes were flooded.
"I don't think people who have lived here a long time have ever seen flooding this bad," Gillen said.
The tidal surge sent damaged boats rushing more than three blocks onto downtown streets in St. Marys, just north of the Georgia-Florida state line, St. Marys Police Lt. Shannon Brock said.
Downtown Atlanta hotels remained full of evacuees. Many milled about the CNN Center, escaping crowded hotel rooms in search of open restaurants. Many were glued to storm coverage on the atrium's big screen. Parents pointed out familiar sites, now damaged, to their children.
"We've been here since Friday night, and we're ready to go home" to Palm Beach County, Florida, Marilyn Torrence said as her 4-year-old colored.
Irma weakened into a tropical depression late Monday, and the National Hurricane Center discontinued all storm surge and tropical weather watches and warnings related to the storm. Meteorologist Keith Stellman said Atlanta's airport recorded sustained winds of 45 mph (72 kph) with gusts up to 64 mph (103 kph). The hurricane center forecast Irma to drop 5 inches to 8 inches (13 to 20 centimeters) or rain across South Carolina and the northern regions of Georgia, Alabama and Mississippi over the next two days.
About 800 flights had been canceled at Hartsfield-Jackson Atlanta International Airport, which remained operational Monday, even as many planes turned corners of the tarmac into a parking lot. Metropolitan Atlanta Rapid Transit Authority suspended all bus and rail services Monday but said it would resume limited service Tuesday morning with plans to expand service as weather conditions improve. Downtown Atlanta's streets were eerily quiet, with restaurants, businesses and schools closed. Traffic flowed easily on the city's interstates, normally a sea of brake lights during rush hours.
Nearly 1.5 million Georgia Power and EMC customers were without power. Alabama Power reported 45,000 outages. Utilities said thousands of employees were prepared to respond, but repairs could take several days.
Georgia's coast was largely empty less than a year after Hurricane Matthew caused $500 million in damage and killed three people last October. In Charleston, South Carolina, the ocean topped the Battery wall that typically protects downtown. Only Hurricane Hugo's direct hit in 1989 and a 1940 hurricane that hit a short way down the coast pushed higher seas.
Smaller communities also were inundated — the entire South Carolina town of Edisto Beach, population 530, was covered with several feet of water, Mayor Jane Darby said, despite a $17 million dune restoration project following Matthew's destruction.
Atlanta Parks and Recreation Commissioner Amy Phuong said six crews were responding to fallen trees around the city as winds and rain intensified. About half the city's land area is covered by trees — more than most urban areas. Savannah's winds caused palm trees to bend and sway. And much of Alabama has pine trees that can snap in high winds.
Firefighters were rescuing people from homes struck by trees near the Florida line in Lowndes County, Georgia. With wind gusts reaching 70 mph (112 kph), authorities imposed a daytime curfew for the 112,000 residents of Lowndes County, which includes Valdosta, county spokeswoman Paige Dukes said.