Hurricane Maria slammed into Puerto Rico on Wednesday as the strongest storm to hit the U.S. territory in nearly 90 years, turning streets into debris-laden rivers, damaging buildings and cutting power, after killing at least nine people in the Caribbean.
Maria, the second major hurricane to roar through the Caribbean this month, was carrying winds of up to 155 miles per hour (250 kph), high storm surges and drenching rains when it made landfall near Yabucoa, on the southeast of the island of 3.4 million people.
Rivers burst their banks and the winds downed trees and damaged homes and buildings, including several hospitals, according to local media. News pictures showed whole blocks flooded in the Hato Rey neighbourhood of the capital, San Juan.
Abner Gómez, head of the disaster management agency, said the hurricane had damaged "everything in its path".
None of the customers of Puerto Rico's Electric Power Authority had any electricity, he said.
Maria weakened to a category three storm with winds of 115 mph (185km/h) as it moved across the island.
"The information we received is not encouraging," Mr Gómez told a briefing, urging people to stay in their homes.
Earlier, Puerto Rico's governor asked President Donald Trump to declare the island a disaster area after the storm unleashed heavy flooding and life-threatening winds.
Governor Ricardo Rossello said major damage was inevitable, although 500 shelters had been established to protect people.