Hurricane Irma set all sorts of records for brute strength before crashing into Florida, flattening islands in the Caribbean and swamping the Florida Keys.
It finally weakened to a Category 2 storm after making landfall in southwestern Florida. It is hugging the coast as it moves north.
Sunday evening, the storm is still raking Florida with devastating storm surges, winds and rain. Its top sustained winds are now 110 mph and the center of the storm is about 15 miles inland from Fort Myers.
The hurricane center says "although weakening is forecast, Irma is expected to remain a hurricane at least through Monday morning."
The center says the eye of Irma should hug Florida's west coast through Monday morning and then push more inland over northern Florida and southwestern Georgia Monday afternoon.
Florida officials are urging people to stay in their homes and shelters, even if it looks like Hurricane Irma has passed.
Miami-Dade County spokesman Mike Hernandez said he's seen reports of people leaving the county's hurricane shelters. It's too early for that, he says: "Just because it seems like the weather is clearing up, that doesn't mean it's safe to get out on the roads.
Miami Dade remains under curfew, much of it without electricity, and with downed power lines, flooding and poor visibility, moving around could be deadly.
Earlier, at around 3:45 p.m. local time, Hurricane Irma made landfall on Marco Island as a Category 3 hurricane.
The National Hurricane Center in Miami said Irma's powerful eye roared ashore at Marco Island just south of Naples with 115-mph (185-kph) winds, for a second U.S. landfall at 3:35 p.m. Sunday.
Category 3 storms have winds from 111 to 129 mph, but 130-mph (21-kph) wind gust was recently reported by the Marco Island Police Department.
Irma's second U.S. landfall was tied for the 21st strongest landfall in the U.S. based on central pressure. Irma's first U.S. landfall in the Florida Keys was tied for 7th.
More than 2.1 million customers have lost power in Florida.
Florida Power & Light reported the numbers Sunday afternoon. The utility, which services much of south Florida, says more than 845,000 of those customers are in Miami-Dade County.
Duke Energy, the dominant utility in the northern half of Florida, has about 13,000 outages with the outer bands of Irma sweeping across the region.
The power companies say they have extra crews on hand to try to restore power — when it becomes safe to do so.
FPL spokesman Rob Gould says an estimated 3.4 million homes and businesses will lose power once the worst of Irma reaches the Florida mainland.
The storm has pushed water out of a bay in Tampa, but forecasters are telling people not to venture out there, because it's going to return with a potentially deadly vengeance.
On Bayshore Boulevard in Tampa, approximately 100 people were walking Sunday afternoon on what was Old Tampa Bay — a body of water near downtown. Hurricane Irma's winds and low tide have pushed the water unusually far from its normal position. Some people are venturing as far as 200 yards (180 meters) out to get to the water's new edge. The water is normally about 4 to 5 feet (1 to 1.5 meters) deep and reaches a seawall.
The U.S. Hurricane Center has sent out an urgent alert warning of a "life-threatening storm surge inundation of 10 to 15 feet (3 to 5 meters) above ground level" and telling people to "MOVE AWAY FROM THE WATER!"
The waters retracted because the leading wind bands of Irma whipped the coastal water more out to sea. But once the eye passes and the wind reverses, the water will rush back in.
Miami City Manager Daniel Alfonso says a second tower crane has collapsed into a building under construction in the city's downtown area. Alfonso told The Associated Press that the crane collapsed in a large development with multiple towers being built by Grand Paraiso.
Another crane collapsed earlier Sunday onto a high-rise building that's under construction in a bayfront area filled with hotels and high-rise condo and office buildings, near AmericanAirlines Arena. Officials said no one was injured as the result of either crane's collapse.
High winds are impeding Miami authorities' ability to reach the cranes, and authorities are urging people to avoid the areas.
Alfonso says the approximately two-dozen other cranes in the city are still upright and built to withstand significant wind gusts.
Irma made landfall just after 9 a.m. at Cudjoe Key, about 20 miles outside Key West, forecasters said. By midafternoon, it was advancing at about 12 mph toward Florida's southwestern corner, which includes Naples, Fort Myers and Sarasota.
For days, forecasters had warned that Irma was taking dead aim at the Miami metropolitan area and the rest of Florida's Atlantic coast.
But then Irma made a more pronounced westward shift — the result of what meteorologists said was an atmospheric tug-of-war between weather systems that nudged Irma and determined when it made its crucial right turn into Florida.
Meteorologist Ryan Maue of WeatherBell Analytics said the entire Florida peninsula will be raked by Irma's right front quadrant — the part of a hurricane that usually brings the strongest winds, storm surge, rain and tornadoes.
Even before Irma arrived, it made a huge swath of the peninsula's bottom half-unrecognizable.
Normally bustling streets were ghost towns. Party stretches including Duval Street in Key West and Ocean Drive in Miami Beach were shuttered. Sunday church services were called off, and theme parks were closed.
The Tampa-St. Petersburg area, with a population of about 3 million, has not taken a direct hit from a major hurricane since 1921. The wind was already picking up in St. Petersburg, some 400 miles north the Keys, and people began bracing for the onslaught.
"I've been here with other storms, other hurricanes. But this one scares me," Sally Carlson said she snapped photos of the waves crashing against boats. "Let's just say a prayer we hope we make it through."
The governor activated all 7,000 members of the Florida National Guard, and 10,000 guardsmen from elsewhere were being deployed.
Forecasters warned that after charting up Florida's west coast, a weakened Irma could push into Georgia, Alabama, Mississippi, Tennessee and beyond. A tropical storm warning was issued for the first time ever in Atlanta, some 200 miles from the sea.
"Once this system passes through, it's going to be a race to save lives and sustain lives," Federal Emergency Management Agency chief Brock Long said on "Fox News Sunday."
With FEMA still dealing with the aftermath of Hurricane Harvey in Houston, Irma could test the agency's ability to handle two disasters at the same time.
Florida Power and Light warned it will take weeks before electricity is fully restored.
Irma at one time was the most powerful hurricane ever recorded in the open Atlantic, with a peak wind speed of 185 mph (300 kph).
Given its size, strength and its projected course, it could prove one of the most devastating hurricanes ever to hit Florida.
The storm brought memories of Hurricane Charley, which blew ashore near Fort Myers in 2004 with winds near 149 mph. It caused $15 billion in damage and was blamed for as many as 35 deaths in the U.S.
Associated Press writers Seth Borenstein in Washington; Tamara Lush in St. Petersburg; Terry Spencer in Palm Beach County; Gary Fineout in Tallahassee; Terrance Harris and Claire Galofaro in Orlando; and Jason Dearen and David Fischer in Miami contributed to this report.