Massive Flooding Feared After Ivan

Hurricane Ivan (search) hurtled through Alabama early Thursday, its fierce winds splitting bridges into pieces and its blinding rains turning roadways into lakes, before weakening to a tropical storm by afternoon and swirling through Georgia.

At least 20 people were killed in the United States, and thousands more were stranded or left without power in the violent but sluggish storm.

By late afternoon, Tropical Storm Ivan was rolling into northern Georgia and the Atlanta region, where heavy rains and winds were causing airline delays of nearly three hours on average at Hartsfield International Airport (search).

Ivan quickly deteriorated to a tropical storm after coming ashore. But forecasters warned it was not done yet: It threatened up to 15 inches of rain and flooding across the South, already soggy after Hurricanes Charley and Frances over the past month.

And more danger could be on the horizon: Tropical Storm Jeanne is tearing through the Caribbean on a path that could take it into Florida early next week.

Ivan's U.S. death toll included 13 in Florida, two in Mississippi, and one in Georgia. In Louisiana, four evacuees died after being taken from their storm-threatened homes to safer parts of the state.

Ivan killed 70 people as it passed through the Caribbean.

For Florida, it was the third storm in five weeks. Hurricane Charley struck the state Aug. 13 and Frances on Sept. 5; the two caused dozens of deaths and billions of dollars in damage.

Ivan knocked out power to more than 1.5 million customers in four states, toppled trees and ripped off roofs. In the beach resort town of Gulf Shores (search), Ala., where the storm's eye came ashore, the sky glowed bright green as electrical transformers blew.

Still, many of the millions of Gulf Coast residents who spent a frightening night in shelters and boarded-up homes emerged Thursday morning to find that Ivan was not the catastrophe they had feared.

"I have no idea what the situation is with my house," Paul Cloos, with the Mobile Register, told FOX News. "One of our reporters had a tree crush his car and it was totaled. He was not in it — he's fine."

Cloos also told FOX of reports of at least two women in the region going into labor during the height of the storm.

"Ivan was nowhere near as bad as Frederic — not even close," Mobile Police Chief Sam Cochran said, referring to the 1979 storm that devastated the Alabama coast. "I think we were really spared and blessed."

New Orleans, especially vulnerable to storms because much of it lies below sea level, had wind and just a touch of rain.

"Leaves in the pool — that's it," said Shane Eschete, assistant general manager of the Inn on Bourbon Street. "It won't take us long to clean that up."

Downtown Mobile was deserted early Thursday. Historic, oak-tree-lined Government Street was blocked with downed tree limbs, metal signs, roofing material and other storm debris.

"We were wondering at first if we made the right choice or not," said Marc Oliver, 38, who rode out the storm with his family in Mobile, moving from room to room as the wind shifted. "We had some trees down in our yard and roofing damage. Other than that, we came out pretty good."

President Bush signed disaster declarations Thursday for Alabama, Louisiana and Mississippi, and was awaiting paperwork from Florida, press secretary Scott McClellan said.

In Florida, two people were killed and more than 200 homes were damaged when at least five tornadoes roared through Bay County. Another tornado killed four people when it struck homes in Blountstown, Fla., and an 8-year-old girl died after being crushed by a tree that fell onto her mobile home in Milton, Fla. Her parents were unharmed.

Six people were killed in Escambia County.

"You want to see the natural hand of God firsthand, but you don't realize how strong it is," said Kevin Harless, 32, who was sightseeing in Panama City Beach, Fla., around the time of the tornadoes.

Four ailing evacuees, including a terminally ill cancer patient, died after being taken from their storm-threatened southern Louisiana homes to safer parts of the state.

Part of a bridge on Interstate 10, the major east-west highway through Florida's Panhandle, was washed away.

Max Mayfield, director of the National Hurricane Center in Miami, warned that the misery would spread as Ivan moved across the Southeast. "I hate to think about what's going to happen inland," he said.

A tropical storm warning remained in effect from the mouth of the Pearl River in eastern Louisiana to Apalachicola, Fla.

National Hurricane Center forecasters said land east of where Ivan's eye passed would experience storm surge of 10 to 16 feet, topped by large and dangerous battering waves.

"We've had calls from folks saying, 'The water is rising. Can you come get me?' Unfortunately we can't send anybody out. The storm is at its worst point now," Sonya Smith, a spokeswoman for Florida's Escambia County emergency management agency, said early Thursday.

The storm's northward track spared New Orleans a direct hit. Parts of the city saw only sporadic, light rain overnight, though wind gusts reached tropical storm strength.

Tolls were being lifted and signal lights adjusted to prepare for heavy traffic as people return home — a reversal of the jammed roads before the storm. Of roughly 2 million told to evacuate ahead of the storm, 1.2 million were from greater New Orleans. Five people were arrested there for alleged looting.

More than 1.5 million homes and businesses lost power: at least 975,000 in Alabama, 50,000 in Louisiana, 145,000 in Mississippi and 345,000 in the Florida Panhandle. Florida workers were also still trying to restore power to about 160,000 hit by Hurricanes Charley and Frances.

Ivan's waves — some up to 25 feet — destroyed homes along the Florida coast Wednesday. A buoy about 300 miles south of Panama City registered one wave of 50 feet high.

Mayors of the Alabama communities of Gulf Shores and Orange Beach refused to let anyone come back for now, fearful that returning residents weren't safe among downed power lines and weakened buildings.

Gulf Shores Mayor David Bodenhamer said streets were flooded, and trees and power lines were down everywhere. His home and others along the beachfront road were OK, he said, "but the beach is going to be a mess, a big mess."

"I think the worst is over but we still have a lot to go … we're not out of the woods yet but I didn't think we'll see anymore 130 mph winds," Alabama Gov. Bob Riley told FOX News Thursday morning.

However, Thursday morning already brought 11 tornadoes to the state, he said.

"It's still a very serious situation here in Alabama," Riley added.

He urged Alabamans to give workers Thursday to clean up potentially dangerous situations, like downed power lines, before returning to their homes.

"We want to get you back just as soon as we can but I would hate to lose a life now because someone stepped into a puddle of water and there's a live wire in it," Riley said.

The National Weather Service issued a flood watch for as far away as North Carolina, which suffered heavy flooding last week from the remnants of Hurricane Frances.

FOX News' Jen D'Angelo, Catherine Donaldson-Evans, Linda Vester, Jonathan Serrie, Jeff Goldblatt and The Associated Press contributed to this report.