MIAMI — Ready or not, Florida found itself face to face with Hurricane Irma’s galloping winds and rains on Sunday, as evacuees and holdouts alike marked uneasy time in homes and shelters from the Keys to the Panhandle, tap-tapping their nearly dead cellphones for news they were frantic to hear but helpless to change.
The hurricane rammed ashore at Cudjoe Key before whirling on the state’s southwest and west coast on the first day of its sodden chug north, buckling two giant construction cranes in Miami and rotating others like clock hands, snacking on trees and power lines, and interrupting millions of lives.
An apocalyptic forecast had already forced one of the largest evacuations in American history. Now it was time to find out what the storm would do — and whether the heavily populated cities of Naples, Fort Myers, St. Petersburg and Tampa were prepared.
“Everybody has a plan until they get punched in the face,” Mayor Bob Buckhorn of Tampa said at a Sunday news conference, paraphrasing the boxer Mike Tyson. “Well, we’re about to get punched in the face.”
Having flattened a string of Caribbean islands and strafed Puerto Rico and Cuba over the last week as a dangerous Category 4 and 5 storm, Irma was downgraded on Sunday afternoon to Category 2, according to the National Hurricane Center. By early Monday morning, the storm had again been downgraded to a Category 1.
The sea was Irma’s ally in destruction. In Key Largo, it annexed backyard pools. In Miami, it poured a salt river down Biscayne Boulevard, the city’s main artery. In Naples and Tampa Bay, it pulled back from the shoreline, leaving waters so shallow that unwary dogs could splash around what remained. But that was only a prelude to a violent return: When the wind changed, scientists warned, the water would hurl itself right back to where it was, and then some.
At least four deaths were reported in Florida after the storm’s arrival on Sunday, adding to a death toll of at least 27 from its Caribbean rampage. More than three million people in Florida were without power, officials said on Sunday night.
Officials along the Gulf Coast had believed they would be spared the worst of the assault until the storm’s trajectory took an unfavorable westward bounce late in the week. After a Saturday spent hastily converting fortified buildings into shelters, they were hurrying the final preparations into place on Sunday.
Curfews were declared in Collier County, which includes Naples; Lee County, which includes Fort Myers; and in Tampa, and officials said they would not be lifted until the storm cleared. Shortly before 5 p.m. Sunday, the Tampa police called officers off the streets as the city confronted consistent wind gusts of more than 40 m.p.h. The westbound lanes on two of the three bridges connecting Tampa with St. Petersburg were closed.
Lest any humans decide to take the weather into their own hands, the sheriff’s office in Pasco County, north of Tampa Bay, was telling local residents not to shoot weapons at the hurricane.
“You won’t make it turn around,” the sheriff’s office tweeted, “& it will have very dangerous side effects.”
Midafternoon in Fort Myers, it was hard to tell which was worse, the wind or the rain.
The wind whipped the tops of palm trees around like pompoms in the hands of a cheerleader. At one Fort Myers hotel, the rain pelted the building with such force that it came into rooms around window frames, stains spreading ever wider on the carpet.
But the Keys, a collection of islands off Florida’s southern tip, met Irma first.
Images showed entire houses underwater. The flooding in Key Largo had small boats bobbing in the streets next to furniture and refrigerators like rubber toys in a bathtub. Shingles were kidnapped from roofs; swimming pools dissolved into the ocean.
“Still whiteout,” John Huston, a resident who had stayed, wrote in a text message to The Associated Press around lunchtime on Sunday. “Send cold beer.”
Local authorities were still waiting out the storm before determining the extent of the flooding and damage. But one of Irma’s casualties was indisputable: The roof of the Key Largo building that local emergency operations officials were using after they fled their headquarters in Marathon had blown off.
On Key West, by contrast, one resident who was able to speak to a reporter by landline described streets pocked with shutters, windows and branches, but no flooding or ravaged houses. The resident, an 81-year-old artist named Richard Peter Matson who has lived in an old townhouse there since 1980, had decided to shelter in his home against all advice.
“If anything was going to happen,” Mr. Matson said, “I wanted to be here to take care of it.”
Those who did evacuate should not come back until local officials had had a chance to inspect the 42 bridges that connect the Keys to each other and to the mainland, said Cammy Clark, a county spokeswoman. As a precaution, officials were asking residents to boil water.
Irma was capricious. The residents of the Miami area, once projected to bear the worst of it, seemed at some points on Sunday to be suffering more from the fidgets than anything else.
As power vanished, their cellphones became their only tether to news, family and friends. When their cellphone batteries died, they dashed out to their cars to recharge.
Yamile Castella and her husband, Ramon, both Miami natives, spent Sunday reading, listening to “Hamilton” and watching “Wonder Woman” until the wind gusts intensified enough to throw half an avocado tree at their house. All the while, Ms. Castella was juggling four chats on WhatsApp — a rowing group, a running group, and two family groups, everyone trading stories about the highest gusts, who was eating what, who was doing what.
“We feel like we’re not alone,” she said.
To the north, most could not yet afford to relax.
By Sunday afternoon, more than half of the 45 shelters in Hillsborough County, which contains Tampa, had filled, including a shelter for people with special medical needs that had sprung up on the floor of the Sun Dome arena at the University of South Florida. There were nearly 800 people there, including patients, volunteers, nurses and doctors, and they were out of cots and pillows. Mike Wagner, the shelter’s manager, had to tell a woman and her family that there was no room.
“We just had to tell her, you have to go back home and hunker down,” Mr. Wagner said. “It’s a patient with five family members and a pet. It’s a sad state of affairs, but you have to draw some limits.”
The floor of the stadium, which is usually the home of the university’s basketball and volleyball teams, was now a patchwork of cots — 435 of them — and medical devices. Patients were hooked into oxygen machines and tucked under plaid or striped blankets. There was a special section for hospice patients, and more cots lined the hallways.
Mr. Wagner’s main worry was trying to ration precious time with the electrical outlets. It was becoming nearly impossible to accommodate new patients who needed electricity around the clock to power their medical equipment.
“We’re physically going to have to unplug someone, we’re telling them, you have to go back home,” Mr. Wagner said. “I don’t even know how that works for them. They’ll have to find some place. But I can’t unplug you, if you need oxygen, just to plug someone else in.”
John Hawrsk, 67, was caring for his 96-year-old mother, whom he was keeping slightly sedated so she would stay calm.
“She gets kind of panicky, there’s a little confusion,” Mr. Hawrsk said. “Try to keep her eyes closed, try to get her to sleep as much as she can on her own.”
North of Irma’s swirl, in Orlando, searchers, canine handlers, doctors and communications experts had come from as far as Los Angeles to help.
Warn your families that Hurricane Irma could end communications home for days, Chuck Ruddell, a member of California Task Force 1, told his teammates. Accept that the team, which worked the aftermath of Hurricane Harvey in Texas, might be sleeping at high schools and fairgrounds for weeks more. And prepare to make snap decisions about who to save first.
Speaking in shorthand, the men and women checked their eight boats, three tractor-trailers and other equipment. They scanned maps of Florida communities. They watched the news.
Then they, too, had nothing more to do but wait.