An aerial photo taken with a drone shows damage in the wake of Hurricane Ian in Fort Myers, Fla., on Thursday. Photo by Tannen Maury/EPA-EFE
Sept. 29 (UPI) -- At least 13 people in Florida have been reported dead from Hurricane Ian, and President Joe Biden said Thursday that he fears a "substantial loss of life."
"[The storm] is still moving across the state today. This could be the deadliest hurricane in Florida's history," Biden said Thursday, while thanking workers in person at the headquarters of the Federal Emergency Management Agency in Washington.
"The numbers are still unclear, but we are hearing early reports of what may be substantial loss of life," Biden said.
Florida's deadliest storm was the 1928 Okeechobee hurricane, which killed more than 2,500 people.
Charlotte County Commissioner Chris Constance said Thursday afternoon that six confirmed deaths had occurred there, just north of Fort Myers, according to CNN.
Lee County Sheriff Carmine Marceno told CNN at least six deaths occurred in his county, which includes the island near Cape Coral -- Cayo Costa -- Ian made landfall on Wednesday.
Another death was reported near Deltona. A 72-year-old man was found unresponsive in a canal near his home. The Volusia County Sheriff's Office said he had walked outside during the storm to drain his pool but never made it back inside.
Authorities said they believe he was using a hose to drain a pool down a hill into a 30-foot-wide canal. They said a steep incline was soft and slippery because of the heavy rain. The man's wife called the sheriff about 1 a.m. EDT to report him missing.
Millions of people remained without power across the state Thursday as rescue crews work to respond to calls of people trapped by high water.
"We're continuing to see deadly rainfall, catastrophic storm surges, roads and homes flooded. We're seeing millions of people without power," Biden said, adding he had spoken with Gov. Ron DeSantis on Thursday morning, pledging federal help.
Biden praised the work of FEMA employees and Homeland Security Secretary Alejandro Mayorkas.
"The Coast Guard deployed 16 rescue helicopters, six fixed-wing aircraft and 18 rescue boats and crew. That's just one element of the many federal search-and-rescue teams that were pre-staged in Florida," Biden said.
DeSantis called the storm "historic."
Officials said the hurricane took out a large section of the Sanibel Causeway connecting Sanibel Island to the mainland. The collapse has left people who stayed on the island stranded. It is unclear how many people remain on the island, which is a popular Florida tourist destination, as well.
FEMA's search-and-rescue teams still were focusing on people in life-threatening circumstances first as of Thursday afternoon.
Ian had weakened to a tropical storm by Thursday as it moved northwest toward the U.S. east coast, where forecasters expected it to strengthen again.
Jacksonville International Airport closed all of its terminals on Thursday ahead of the storm's approach, while Key West International Airport reopened. Orlando International Airport said it would reopen Friday.
The Sarasota-Bradenton International said it expected to reopen Thursday night and Tampa International at noon Friday. The St. Petersburg-Clearwater International and Southwest Florida International airports in Fort Myers said they would reopen Friday at noon.
More than 2.6 million people were without power by Thursday afternoon, with at least three counties reporting near complete blackouts and 10 showing that more than 50% of customers were in the dark, according to poweroutage.us.
Meanwhile, more than 20 Cuban migrants whose boat sank off the Florida Keys on Wednesday were still missing.
Chief Patrol Agent Walter Slosar of U.S. Border Patrol's Miami sector said the boat with 27 migrants onboard sank due to the inclement weather shortly before Hurricane Ian hit the Florida Keys.
Agents initiated a search-and-rescue operation after four of the migrants swam to Stock Island's shore.
The U.S. Coast Guard later said crews were able to rescue another three people in waters about 2 miles south of Boca Chica, with air crews still searching for other survivors.
In Collier County, which encompasses the city of Naples, the sheriff's office Wednesday night said its East Naples deputies had conducted 30 rescue missions throughout the day with more ongoing.
"Water is everywhere," the office said late Wednesday. "There will be damage."
The sheriff's office had said a few hours earlier that it was in "triage mode" and was responding to a "significant number of calls" from people trapped in their homes due to water.
Naples warned late Wednesday that half of its streets were made impassable due to high water and that tides may further bury them.
The National Oceanic and Atmospheric Administration said water levels in Naples had reached more than 6 feet above normal tide ahead of Ian's landfall Wednesday, eclipsing the previous record of 4.25 feet set during 2017's Hurricane Irma.
Naples was under a curfew until further notice. The Naples Fire-Rescue Department has also issued a precautionary boil water notice for its entire drinking water service area.