Homes are flooded on Salinas Beach after the passing of Hurricane Fiona in Salinas, Puerto Rico, Monday, Sept. 19, 2022. AP
Forecasters said Fiona could become a major hurricane late Monday or on Tuesday, when it was expected to pass near the British territory.
"Storms are unpredictable,'' Premier Washington Misick said in a statement from London, where he was attending the funeral of Queen Elizabeth II. "You must therefore take every precaution to ensure your safety.''
Misick was scheduled to return home on Thursday.
Fiona was centered 80 miles (130 kilometers) southeast of Grand Turk Island late Monday. It had maximum sustained winds of 110 mph (175 kph) and was moving north-northwest 10 mph (17 kph).
The intensifying storm kept dropping copious rain over the Dominican Republic and Puerto Rico, where a 58-year-old man died after police said he was swept away by a river in the central mountain town of Comerio.
Another death was linked to the blackout, a 70-year-old man who was burned to death after he tried to fill his generator with gasoline while it was running, officials said.
The National Guard has rescued more than 900 people as floodwaters continue to rush through towns in eastern and southern Puerto Rico with up to 30 inches (76 centimeters) of rain forecast for some areas. Multiple landslides also were reported.
The blow from Fiona was made more devastating because Puerto Rico has yet to recover from Hurricane Maria, which killed nearly 3,000 people and destroyed the power grid in 2017. Five years later, more than 3,000 homes on the island are still covered by blue tarps.
Authorities said at least 1,300 people and some 250 pets remain in shelters across the island.
Fiona sparked a blackout when it hit Puerto Rico's southwest corner on Sunday, the anniversary of Hurricane Hugo, which slammed into the island in 1989 as a Category 3 storm.
By Monday night, authorities said they had restored power to more than 114,000 customers on the island of 3.2 million people.
Puerto Rico Gov. Pedro Pierluisi has warned it could take days before everyone has electricity.
Water service was cut to more than 837,000 customers, two thirds of the total on the island, because of turbid water at filtration plants or lack of power, officials said.
Forecasts called for Fiona to grow into a major hurricane of Category 3 or greater. It was on a path to pass close to the Turks and Caicos islands on Tuesday and was not expected to threaten the U.S. mainland.
In the Dominican Republic, authorities reported one death: a man hit by a falling tree. The storm displaced more than 12,400 people and cut off at least two communities.
The hurricane left several highways blocked, and a tourist pier in the town of Miches was badly damaged by high waves. At least four international airports were closed, officials said.
The Dominican president, Luis Abinader, said authorities would need several days to assess the storm's effects.
Fiona previously battered the eastern Caribbean, killing one man in the French territory of Guadeloupe when floodwaters washed his home away, officials said.