Hurricane Ian left a path of destruction in southwestern Florida, trapping people in flooded homes and knocking out power to 2.5 million people.

One of the strongest hurricanes to ever hit the United States barrelled across the Florida peninsula overnight on Wednesday, threatening catastrophic flooding inland, the National Hurricane Center warned.

Ian turned streets into rivers and blew down trees as it slammed into southwest Florida with 241 kilometre (150 miles) per hour winds, pushing a wall of storm surge. Ian’s strength at landfall was Category 4 and tied it for the fifth-strongest hurricane – when measured by wind speed – to ever strike the United States.

It dropped to a tropical storm early Thursday over land, but was expected to intensify again once its centre moves over the Atlantic Ocean and menaces the South Carolina coast on Friday at near-hurricane strength.

Storm surges as high as two metres (six feet) were expected on both sides of the peninsula.

Life-threatening storm surges and hurricane conditions were possible along the coasts of northeast Florida, Georgia, and South Carolina.