It started with winds of 210 kilometres per hour battering the Texas shore. Then as the most powerful hurricane to hit the US in more than a decade made its way inland, leaving a trail of shredded trees and wrecked roofs, the gusting winds eased and the realisation dawned that with imminent catastrophic flooding the worst may be still to come.
No deaths have been reported, but emergency workers said they were still struggling to get to the areas worst affected by Hurricane Harvey, and fear residents may be trapped in collapsed homes.
The town of Rockport, Texas, was one of the hardest hit. Hours before Harvey arrived, local officials told anyone ignoring an evacuation order should write their names and social security numbers on their arms to help identification
The dawning day revealed a broken moonscape of debris and twisted trees. At least 10 people were injured when the roof of an old people’s home collapsed.
Charles "CJ" Wax, the mayor, said emergency services were hampered by the loss of cell phone services.
"We know there is widespread devastation," he told the Weather Channel. "I think it’s safe to say we took a Cat. 4 (hurricane) right on the nose, and we’d appreciate everyone’s prayers." It was too early to know if his city had suffered fatalities, he added.
Harvey is the most powerful hurricane to hit the state of Texas in more than 50 years. It made landfall as a category 4 – the second strongest of five classifications - in an area of huge economic importance, home to oil facilities and America’s fourth largest city, Houston.
It weakened significantly on Saturday as it inched inland at about 10kph, according to the US hurricane centre. Its wind speed dropped to 120 kph, reducing it to a category one hurricane. But the authorities believe Harvey has more to give, weakening to tropical storm status but continuing to criss cross the coast, bringing storm sea surges of up to four metres and dumping more than 90cm of rain as it circles Texas over the next four days.
By dawn, more than half a metre of rain had fallen in some places.
Near Galveston, motorists on a major interstate road were forced to stop under bridges as torrents of rain reduced visibility to almost nothing.
Hurricane Harvey is Donald Trump’s first major natural disaster as president. His Republican predecessor George W Bush suffered intense criticism for the handling of Hurricane Katrina by federal agencies in 2005, when at least 1200 people died in the storm and subsequent floods.
Mr Trump said he had signed a disaster proclamation which “unleashes the full force of government help” shortly before Harvey made landfall.
On Saturday he tweeted, “Closely monitoring #HurricaneHarvey from Camp David. We are leaving nothing to chance. City, State and Federal Govs. working great together!”
He also praised Brock Long, the head of the Federal Emergency Management Agency (Fema), for his handling of the crisis so far.
The president is expected to visit Texas after the storm has passed. Mr Bush was criticised for surveying the damage caused by Hurricane Katrina from the presidential plane, Air Force One, instead of going to the scene.
About six million people are believed to lie in Harvey’s path as well as vital parts of America’s petrochemical industry.US petrol prices spiked as more than a fifth of Gulf of Mexico oil production shut down, according to the US government.
The National Weather Service has warned that parts of southern Texas could be uninhabitable for weeks or months. Two utilities companies reported a combined total of more than 240,000 customers without power, a number that was expected to grow.