CORPUS CHRISTI, Texas — A day after roaring ashore as a hurricane, Hanna lashed the Texas Gulf Coast on Sunday with high winds and drenching rains that destroyed boats, flooded streets and knocked out power across a region already reeling from a surge in coronavirus cases.

Downgraded to a tropical storm, Hanna hovered over the U.S.-Mexico border with winds near 50 mph (85 kph), the National Hurricane Center said. It was expected to unload as much as 18 inches of rain (45 centimetres) on parts of South Texas and northeastern Mexico.

Border communities whose health care systems were already strained by COVID-19 cases — with some patients being airlifted to larger cities — found themselves grappling with Hanna.

Dr. Ivan Melendez, the health authority in Hidalgo County, Texas, was treating a patient overnight at a hospital when he noticed water pooling on the floor.

“I thought, ‘Hey, something’s leaking,’” Melendez said. “The nurse looks at me and says, ‘Look behind you.’ I look and see this water coming and coming and coming down the wall.”

The water was flowing through a vent in the room, which had been retrofitted with a fan to create negative pressure and prevent the virus spreading through the hospital.

After driving home in the storm in the middle of the night, Melendez was trapped Sunday morning in his home by downed trees and had no electricity. He used the phone to discuss whether to place a 58-year-old woman on a ventilator, a decision he felt uncomfortable making without seeing the patient in person.

“You look at the people’s eyes,” he said. “You’ll know if they’re in despair.”

A community building known as the “Dome” in the border town of Mercedes was set aside for evacuees who had tested positive for COVID-19 or were exposed to the virus. Across the region, shelters were also opened in hotels, schools and gyms.

Henry Van De Putte, CEO of the Red Cross’ Texas Gulf Coast chapter, said the organization would open more shelters with reduced capacity to ensure social distancing. Volunteers and people seeking refuge will undergo temperature checks, and a medical professional will be assigned to each location, he said.

He emphasized that people should not delay seeking help because of the virus.

“Yes, coronavirus provides risk, but so does floodwater, so does not having electricity, so does not having required medications,” he said. “We’re doing everything we can do possible to make it a safe environment.”

Coastal states scrambled this spring to adjust emergency hurricane plans to account for the virus, and Hanna was the first big test. Gov. Greg Abbott said Saturday that some people in need of shelter would be given hotel rooms to keep them apart from others.

Abbott announced Sunday that the Federal Emergency Management Agency approved an emergency declaration that will provide federal aid.

The first hurricane of the 2020 Atlantic season blew ashore as a Category 1 storm late Saturday afternoon with winds of 90 mph not far from Port Mansfield, which is about 130 miles south of Corpus Christi.

Parts of South Texas had gotten at least 9 inches of rain, including Cameron County, which includes Brownsville.

Myrle Tucker, 83, tried to ride out the storm in a powerboat docked in a Corpus Christi marina. But winds and rain blew out the vessel’s windows. Eventually rescuers in a dinghy were able to reach him and bring him to shore.

Tucker was standing in the marina Sunday holding a cup of coffee. Many other boats had been flooded and lashed by the storm. He recalled telling the rescuers he wasn’t sure he would be able to climb out of his boat.

“They picked me up,” he said. “They carried me like a box of napkins.”

The Coast Guard helped rescue a couple without injuries after their sailboat began taking on water Saturday evening in a harbor near Corpus Christi.

More than 155,000 customers were without power Sunday afternoon throughout South Texas, including Corpus Christi, Harlingen and Brownsville, according to AEP Texas.

Corpus Christi is in Nueces County, where health officials made headlines when they revealed that 60 babies tested positive for COVID-19 from July 1 to July 16. Farther south in Cameron County, more than 300 new cases have been reported almost daily for the past two weeks. The past week has also been the county’s deadliest of the pandemic.

Hanna came nearly three years after Hurricane Harvey blew ashore northeast of Corpus Christi. Hanna was not expected to be as destructive as Harvey, which killed 68 people and caused an estimated $125 billion in damage in Texas.

Mexico’s northeasternmost states, Tamaulipas and Nuevo Leon, also took precautions ahead of the storm. Tamaulipas disinfected shelters to try to avoid spreading COVID-19, authorities said.

In the Mexican city of Matamoros, across from Brownsville, volunteers kept a close eye on Hanna as the rains shook tents in a refugee camp housing an estimated 1,300 asylum seekers, including newborns and elderly people. They have been waiting for months for court dates under a U.S. immigration policy that requires them to remain in Mexico.

In the Pacific Ocean, meanwhile, Hurricane Douglas closed in on Hawaii over the weekend.