Hurricane Sally, which slammed Florida and Alabama as a powerful Category 2 storm, left heavy flooding, destroyed buildings, more than 400,000 homes and businesses without power, and at least one person dead.
"It looks like a war zone to me," a Florida resident told NBC's "TODAY" on Thursday.
The system was still producing heavy rainfall for the eastern Carolinas and southeast Virginia, federal forecasters said. Tornadoes were possible as it moved east-northeast at 24 miles per hour, they said.
Sally, which has since been downgraded to a post-tropical depression, deluged parts of Pensacola on the Florida Panhandle with nearly 30 inches of rain, causing some streets to look like rivers with whitecaps at times.
In nearby Orange Beach, Alabama, the mayor's office confirmed there is one fatality and one person missing in connection with the storm. It did not offer details.
Eric Gilmore, head of emergency management in Pensacola's Escambia County, said at a news conference Thursday that the Escambia River was expected to continue rising and flood homes Friday.
The Escambia County Sheriff's Office and U.S. Coast Guard officials said Thursday they were searching for 27-year-old Brandon Nicholson, last seen Wednesday morning trying to retrieve his pontoon boat in Perdido Bay.
The main bridge between Pensacola and Pensacola Beach had a section knocked out when a barge-mounted construction crane came loose.
In Gulf Shores, Alabama, where the hurricane made landfall Wednesday morning, resident Holli Deere said, "It sounded like a freight train, a never-ending freight train. When it was over, there was just silence."
But Deere, 37, who splits her time between Gulf Shores and Foley, said the aftermath of the hurricane is the hardest part as residents find themselves living amid destruction and without power.
"We treat it as if we are camping," she said of having no power.
Orange Beach officials warned residents Wednesday, "Stay off the roads and be at your destination before dark as downed power lines, potential gas leaks, debris on roads exist."
Sally weakened to a post-tropical depression Wednesday but was cutting a swath through the Southeast on Thursday, putting 20 million people from Georgia through southeastern Virginia under flash flood alerts and 6 million at the risk of severe storms.
Florida Gov. Ron DeSantis warned people in flooded areas that as water from the hurricane subsides, heavy rains to the north were expected to cause flooding in Panhandle rivers in the coming days.
“So this is kind of the initial salvo, but there is going to be more that you’re going to have to contend with,” he said.
DeSantis also said at a news conference that residents should expect a lot of property damage from the flooding.
"When you see downtown Pensacola and you see 3 feet of water there, that's going to affect probably every business," the governor said.
In Navarre, Florida, about 23 miles east of Pensacola, resident Christina Ropp, 33, said many streets in her neighborhood were impassable from the flooding.
"It seems like the majority of the damage here is from flooding and storm surge," Ropp said Thursday. "At Navarre Beach, we heard reports that waters were waist-high in some spots."