[BBC] Hurricane Maria has knocked out power to the entire island of Puerto Rico, home to 3.5m people, emergency officials have said.
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.
The devastating storm has already left seven people dead on the island of Dominica, which was badly affected on Monday.
Aerial footage shows flattened houses and the death toll on Dominica is likely to rise, with details remaining scant as communication links are down.
Images shared on social media show roofs being stripped away as winds as strong as 140 mph (225 km/h) whipped trees and power lines in Puerto Rico’s capital city, San Juan.
Maria made landfall in Yabucoa in the east of Puerto Rico early on Wednesday, according to the US National Hurricane Center (NHC).
The US territory is facing $73bn (£53bn) in public debt and the damage left by Maria could exacerbate its financial crisis. Declaring a disaster would mean the island could receive more federal assistance in its recovery.
“God is with us; we are stronger than any hurricane,” Mr Rossello said. “Together we will rise again.”
Puerto Rico has experienced just one category five storm since 1851 – the Okeechobee Hurricane in 1928.
Maria is the second storm of this strength to hit the Caribbean this hurricane season – the first being category five Irma earlier in September. Maria began moving roughly along the same track as Irma.
Officials in Puerto Rico feared the debris left by Irma could prove extremely dangerous in the high winds.
People across Puerto Rico are just trying to ride out this storm as best they can now. From where we’re hunkered down, in San Juan, the powerful winds are creating an incredible noise, rattling storm shutters and doors almost off their hinges.
The electricity is out in our hotel and it is too dark and too dangerous to try to see what is happening outside. Like millions of others, we have little choice at present except to stay put and wait in the darkness for the huge hurricane to pass.
The difficulty is, it is moving slowly – giving Maria more time to unleash its power on the island and its infrastructure. Some projections have shown the storm covering the entire island in the coming hours, hitting Puerto Rico with sustained hurricane force winds and large amounts of rainfall.
Hurricane Maria is now the strongest storm to make landfall on the island in almost a century. Most are just praying that when they can eventually emerge from their places of shelter, they and their loved ones are safe and that the damage hasn’t been too extensive.