Hurricane Irma is closing in on the Florida Keys, as thousands of people nervously wait to find out whether their homes will be spared or savaged by the furious storm.
Devastating 130mph winds and catastrophic flooding is forecast, while storm surges of 15ft (4.6m) could be enough to engulf houses in low-lying coastal areas.
Gusts of more than 80mph have already reached the Florida Keys, with the National Weather Service (NWS) predicting more intense winds will arrive by 7am local time (12pm UK time).
The hurricane is beginning to speed up, moving north west at 8mph (13kph) as it approaches land.
In a tweet, the NWS warned “the worst is yet to come” – urging those exposed to the category four storm to stay indoors, hunker down away from windows, and to use “whatever you have to try and protect yourself from flying debris”.
Forecasters are monitoring a crucial shift in Hurricane Irma’s path that could keep the storm’s ferocious eye off the southwest Florida coast and over warm Gulf waters.
If the storm swings to the west, Tampa and Miami could be spared the catastrophic head-on blow that meteorologists have been warning about for days.
Any change in trajectory puts other communities in the firing line – including the city of St Petersburg.
For those trying to flee and seek refuge inland, the changing forecast has caused concern.
“Not only did we go west, but so did Irma. She’s tracking us, that feisty minx,” said Chris Cardona, who has fled his mobile home near Miami with his wife Laurie.
Hurricane Irma is up to to 400 miles wide, leaving the entire Florida peninsula exposed.
The storm killed at least 27 people as it swept across the Caribbean – and in Florida, America’s third-most populous state, officials are also treating Irma as a “life-threatening situation”.
Right now, at least 260,000 people in Florida are without power. The streets of Miami, a usually bustling city, were desolate as an overnight curfew was imposed.