Residents in Florida are anxiously bracing for life-threatening tidal surges, floods and winds as Hurricane Ian approaches.
The storm has already thrashed western Cuba and is expected to intensify before it makes landfall in Florida, reports the BBC.
The Tampa Bay region, which is home to more than three million people, is among the most vulnerable places in the US for severe flooding.
The region could see its first direct hit by a major hurricane since 1921.
“It’s been around 100 years since Tampa had a direct hit. They’ve just been lucky for a long time,” said Erik Salna, associate director of the International Hurricane Research Center.
Low elevation, rising sea levels, and a large population increase the risk of a catastrophic tidal surge. The Tampa area has all three, according to Salna.
If hit directly, the region could be “unrecognisable” in the next couple of days, he said. “The potential is there.”
Hurricane Ian – currently a category three storm, packing winds up to 195km/h (120mph) – is forecast to gain strength as it moves northbound into Florida, passing over the Gulf of Mexico’s warm water on the way.
Tornados have been seen in southern Florida, the National Weather Service said, as Ian approaches the coast. Winds could reach up to 140mph before it makes landfall.
Ian is likely to lose speed as it nears Florida, effectively prolonging the storm’s effects and threatening up to 20in (1.6ft) of rain in some areas.
And if it does hit Tampa, it will strike one of the state’s most densely populated areas.
Over the last 50 years, development has surged along the Tampa region’s nearly 700 miles (1,1200km) of shoreline, with people and buildings scattered along the mostly low-lying beach.
“We’ve moved toward the coast, we’ve moved toward the water. This is, in its own way, a human nature trainwreck,” said Richard Olson, director of the extreme events institute at Florida International University (FIU).