Federal officials estimated one-quarter of all homes in the Keys were destroyed.
The Tampa skyline in the background as local residents (L-R) Rony Ordonez, Jean Dejesus, and Henry Gallego take photographs after walking into Hillsborough Bay ahead of Hurricane Irma in Tampa, Fla., on September 10, 2017.
"There clearly is going to be an impact on GDP in the short-run, we will make it up in the long run", Mnuchin said.
More than 6.5 million Florida homes and businesses are now without power after Hurricane Irma moved through the state, according to the state's emergency management division. A number of county school districts, where schools have been converted into shelters, will remain closed later into the week. More than 100,000 customers were without power in Georgia and over 80,000 in SC. At least 35 were killed in the Caribbean.
"We're all hanging in there, ready to get out there to help others as soon as it's safe to do so", Marco Island Police Chief Al Schettino said as the storm hit his city on Sunday afternoon. "This state is a state of strong resilient people". Florida's largest city, Miami, was spared the brunt of the storm but was still battered. But main traditional supply lines are limited because of the storm. But in the Keys, he said, "there is devastation". "But they're going to be most acute on the coast".
An aircraft carrier was positioned off Key West to help in the search-and-rescue effort.
Irma killed two people in Georgia and four in SC. They headed back out later in the day. The NWS said "most flood deaths occur in vehicles", and added, "turn around, don't drown when encountering flooded roads".
It was undoubtedly an epic hurricane - it travelled 3,700 miles (6,000km), stayed a hurricane for 11 days, and dumped 400mm (15 inches) of rain in some places. I talked to the mayor a short time ago who told me he believes people, even though the track changed 24 hours ago, that people did heed the call to get out.
Authorities plan to fly over the Keys on Monday, officials said. A city employee in Columbia, South Carolina, died Monday after being critically injured in a vehicle crash as he responded to a report of a downed tree, the city said.
Florida Governor Rick Scott said: "So many areas that you would never have thought have flooded, have flooded".
Over the next two days, Irma is expected to push to the northwest, into Alabama, Mississippi and Tennessee.
In fact, the storm surge flooding in Jacksonville broke a record, according to the National Weather Service.
Storm surge and rainfall arriving at high tide Monday afternoon swamped communities along Georgia's 100-mile coast. All mandatory evacuation orders had been lifted by Tuesday, the Jacksonville Sheriff's Office said.
Briton Claudia Knight said her partner Leo Whitting, 38, was stranded on the island of Tortola in the British Virgin Islands archipelago.
Another hurricane, Jose, has been weakening over the western Atlantic, with swells due to affect parts of Hispaniola (the island split into Haiti and the Dominican Republic), the Bahamas, and the Turks and Caicos Islands, later this week.