Last Updated Sep 12, 2017 6:04 PM EDT
MIAMI -- Search-and-rescue teams made their way into the Florida Keys' farthest reaches Tuesday, while authorities rushed to repair the lone highway connecting the islands and deliver aid to Hurricane Irma's victims. Federal officials estimated one-quarter of all homes in the Keys were destroyed.
Two days after the storm roared into the Keys with 130 mph winds, residents were allowed to return to the parts of the Keys closest to Florida's mainland. But theremained a question mark because communications and access were cut off in places.
"It's going to be pretty hard for those coming home," said Petrona Hernandez, whose concrete home on Plantation Key with 35-foot walls was unscathed, unlike others a few blocks away. "It's going to be devastating to them."
Elsewhere in Florida, life inched closer to normal, with some flights again taking off, many curfews lifted and major theme parks reopening. Cruise ships that extended their voyages and rode out the storm at sea began returning to port with thousands of passengers.
The number of people without electricity in the late-summer heat dropped to around 10 million -- half of Florida's population. Officials warned it could take 10 days or more for power to be fully restored. About 110,000 remained in shelters across Florida.
At least 13 people died during Irma, including six in Florida, three in Georgia and four in South Carolina, CBS News confirms. At least 35 people were killed in the Caribbean.
"We've got a lot of work to do, but everybody's going to come together," Florida Gov. Rick Scott said. "We're going to get this state rebuilt. This state is a state of strong resilient people."
The Keys appeared to be the hardest-hit part of Florida, even though the 400-mile-wide storm engulfed nearly the entire state. Drinking water was cut off, all three of the islands' hospitals were closed, and the supply of gas was extremely limited.
Federal Emergency Management Agency administrator Brock Long said that preliminary estimates suggested that 25 percent of the homes in the Keys were destroyed and 65 percent sustained major damage.
"Basically every house in the Keys was impacted," he said.
Officials said it was not known how many people ignored evacuation orders to stay behind in the Keys.
An aircraft carrier was positioned off Key West to help in the search-and-rescue effort. And crews worked to repair two washed-out, 300-foot sections of U.S. 1, the lone highway from the mainland, and check the safety of the 42 bridges linking the islands.
Authorities were stopping people to check documentation such as proof of residency or business ownership before allowing them back into the Upper Keys, including Key Largo, Tavernier and Islamorada.
But the Lower Keys -- including the chain's most distant and most populous island, Key West, with 27,000 people - were still off-limits, with a roadblock in place where the road was washed out.
Corey Smith, a UPS driver who rode out the hurricane in Key Largo, said though it was a relief that many buildings on the island escaped major damage, those who sought to return should recognize conditions were still not good, with branches blocking roads and supermarkets remaining closed.
"They're shoving people back to a place with no resources," he said by telephone. "It's just going to get crazy pretty quick."
Lower Keys resident Leyla Nedin said she doesn't plan to return anytime soon to her home near where Irma came ashore on Cudjoe Key.
"We are still without water, power, sewer, gas and cell service," she said. "My concern is that even if we get to go in to the Lower Keys, our fragile infrastructure could be even more compromised."
Irma's rainy remnants, meanwhile, pushed through Alabama and Mississippi after drenching Georgia. Flash-flood watches and warnings were issued around the Southeast.
In a parting blow as Irma exited Florida, it caused record flooding in the Jacksonville area, where the sheriff's office reported rescuing at least 356 people. On its Twitter account, the sheriff's office said it hopes "people who had their lives saved yesterday will take evacuation orders seriously in the future."
Eddie Hinan waded through knee-deep water to reach his flooded apartment in the San Marco neighborhood of Jacksonville on Tuesday, staying just long enough to grab a plastic bag of clean clothes. His girlfriend, Deborah Smith, waited behind, struck by the devastation around her.
"I just started crying," she said. "I already knew it was gone, the apartment and everything in it. We lost everything."