There have been 12 Hurricane Irma-related deaths throughout the state of Florida, Alberto C. Moscoso, a spokesman for Florida Division of Emergency Management, said Tuesday evening.
As nightfall approached Tuesday, many people from South Carolina to Florida were staying in darkened homes, dealing with fallen trees and blocked roadways, and hoping they could find gas.
The situation in the Sunshine State was trying the patience of people who rode out the storm and those who came home to find widespread devastation and access to their neighborhoods limited at times.
Photos of Hurricane Irma's destruction
Power outages in Florida affected almost 5 million homes, organizations and businesses, among them gas stations, which need the electricity to keep pumps working.
Two days after Irma made landfall on Cudjoe Key, authorities and a few residents were finally able to reach some of the Florida Keys on Tuesday.
What they found was devastating: Based on initial estimates, 25% of the houses on the chain of islands have been destroyed, the Federal Emergency Management Agency said Tuesday. Another 65% suffered major damage.
"Basically, every house in the Keys was impacted some way," FEMA Administrator Brock Long said.
It's still not clear how many casualties Irma caused on the Keys.
It's a long wait for those sifting through what's left of their homes throughout Florida in the oppressive heat and high humidity -- doing so while they wait for the power, and thus the air conditioning, to come back on.
All customers who lost electricity on the eastern side of the state will likely have power restored by the end of this weekend, Florida Power & Light said Tuesday.
An FPL official told reporters at a Broward County news conference that of the 790,000 customers in that county who lost power, 330,000 had their electricity restored Tuesday.
The company is focusing its efforts first on schools, hospitals and other critical infrastructure. Gas stations and restaurants are next on the plan, the official said.
Customers on the west coast of Florida, where Hurricane Irma made its final landfall, will likely have power restored by September 22, the company has said.
But residents like William Rose have bigger concerns. Rose still can't reach his family on the Florida Keys, where about a quarter of the islands' houses are annihilated.
He's not sure whether his mother, stepdad, grandmother and aunt survived Irma's wrath.
"I have no idea, but I'm trying to stay positive," Rose said.
Before the Keys lost cellphone service, Rose received a text from his mother, who chose not to evacuate.
"This is terrible. I will never do this again," the text read. "I'm so glad you got out."
Roadwork in the Keys
Transportation officials are trying to determine whether bridges between the islands can withstand any weight.
The Florida Department of Transportation is repairing two sections of US 1 that were washed away by Irma, one at mile marker 37 and the other at mile marker 75.
Darwin Tabacco, who stayed on Big Pine Key during Irma, is one of the fortunate residents. Both he and his house survived.
"A lot of people lost everything," he said Tuesday morning. "There's homes blown off the stilts. There's power lines down all over the place. Trees completely uprooted. People's businesses flooded. Septic fields flooding. It's just terrible."
More than 5.5 million customers without power
Massive power outages are crippling much of the Southeast on Tuesday. Among the hardest hit by Irma (as of 6 p.m. ET):
Florida: About 4.7 million customers -- which includes homes, organizations and businesses -- are without power across the state, authorities said. Georgia: Almost 850,000 customers are in the dark, according to Georgia Power and Georgia EMC. South Carolina: Almost 90,000 customers have no power, according to Duke Energy and SCE&G. North Carolina: More than 36,000 customers don't have electricity, according to Duke Energy. Alabama: More than 7,000 customers are without electricity, Alabama Power said.
Florida governor: Returning home may be dangerous
Beyond the Keys, Floridians were anxious to return and see how their homes weathered the storm. But officials urged patience.
"Check with local officials before returning home to make sure you can safely do so," Gov. Rick Scott said Monday.
"Don't think just because this thing passed, you can run home. We've got downed power lines all across the state. We've got roads that are impassible still across the state. We've got debris all over the state."
Flights, hospitals will be back online
While the Keys have an exhaustive recovery ahead, signs of normalcy will pop up Tuesday elsewhere in Florida.
Many of Florida's airports are scheduled to reopen with limited operations Tuesday.
And Florida Hospital, a health provider in the state, said it plans to reopen many of its impacted facilities on Tuesday or Wednesday.
Even a weakened Irma engulfed cities as far north as Charleston, South Carolina, on Tuesday.
"I really didn't expect it to become this bad here," Charleston resident Mike Stusnick said Tuesday. "It came in really fast last night. ... We were just praying that it didn't come all the way into the house, and it didn't."
Jacksonville, Florida -- the largest city by area in the contiguous United States -- is still trying to recover from record-breaking storm surge and flooding on Monday.
More than 300 people have been rescued in Jacksonville, the governor said Tuesday.
"So many areas that you thought wouldn't flood, flooded," Scott said.
Irma's deadly trail -- and questions about climate change
Before slamming into the United States, Irma hit Cuba late Friday as a Category 5 hurricane. Irma killed 36 people in the Caribbean before heading to the United States.
This is the first year on record that the continental United States has had two Category 4 hurricane landfalls in the same year. Last month, Hurricane Harvey devastated much of coastal Texas and killed more than 70 people.
At a news conference Tuesday, both the FEMA administrator and acting DHS Secretary Elaine Duke avoided explicitly answering questions about whether Washington needs to focus more on climate change after Harvey and Irma.
Instead, Long and Duke stressed the need for preparedness and resiliency.