Large-scale evacuations are underway along America's east coast ahead of the arrival of Hurricane Matthew - one of the fiercest storms of recent times.
The category three storm - with winds reaching 145 mph - has left a trail of destruction and cost the lives of an estimated 26 people during its rampage through Cuba, Haiti, the Dominican Republic and now the Bahamas.
Forecasters say the storm could hit Florida as early as Thursday before making its way up the coast over the weekend.
Nearly two million people across Florida, Georgia and South Carolina have been told to leave coastal areas and move to higher land.
President Barack Obama, speaking after a briefing with the Federal Emergency Management Agency on Wednesday, urged Americans to heed the warnings of officials and take evacuation orders seriously, describing the storm's potential impact as "devastating".
Florida's governor Rick Scott warned his residents to prepare for a direct hit that could be "catastrophic" as he called on those in high-risk areas to evacuate "before it's too late".
"People have less than 24 hours left to prepare, evacuate and shelter," Governor Scott said.
In Georgia, a state of emergency has been declared in more than a dozen counties while officials in South Carolina say an estimated 250,000 people were evacuated from coastal areas on Wednesday with more expected to leave on Thursday.
The warnings prompted many to rush to local stores and gas stations to stock up on food, water, fuel and medicine, although many were greeted by long queues and empty shelves.
Huge traffic jams were also seen in South Carolina as residents attempted to flee.
Matthew would be the biggest hurricane to make landfall in the US since Wilma in 2005, which killed five people and caused billions of pounds worth of damage.
The preparations in the US came as rescuers in Haiti - one of the world's poorest nations - tried to reach isolated areas and determine the full extent of the death and destruction left behind.
Heavily-flooded residential areas, debris strewn across roads and the collapse of a bridge severely hampered rescue efforts.
Reports also suggested that overcrowded hospitals were running low on fresh water.
The hurricane will be the biggest humanitarian crisis to hit the country since the deadly earthquake of 2010, which claimed more than 200,000 lives.