Officials have urged millions of residents in Florida and South Carolina to move inland as Hurricane Matthew approaches. The weather system has caused at least 23 deaths in Haiti alone.
Hurricane Matthew pounded the Bahamas as it barrels towards the southeast United States, where hundreds of thousands of people fled coastal areas ahead of expected landfall late Thursday.
Packing sustained winds of about 115 miles per hour (185 kph), the category 3 hurricane is expected to develop into a category 4 as it nears the east coast of Florida, the US National Hurricane Center predicted.
Evacuations, some mandatory, were being put in place in about a dozen of Florida's coastal counties.
"People have less than 24 hours to prepare," Florida Governor Rick Scott said. "Having a plan could be the difference between life and death."
Hurricane-driven storm surges, heavy rainfall and wind has the potential to cause significant harm to life and property.
"This is a serious storm," US President Barack Obama said Wednesday after he met officials at the Federal Emergency Management Agency (FEMA) in Washington. "If there is an evacuation order in your community, you need to take it seriously."
In advance of the hurricane making landfall, FEMA sent personnel to emergency centers in Florida, Georgia, South Carolina and North Carolina. Governors in all of those states have declared states of emergency, allowing them to mobilize the National Guard.
The National Hurricane Center predicted that after slamming Florida late Thursday the hurricane was likely to move northward and impact Georgia and South Carolina by late Friday.
More than 12 million people were under hurricane watch or warning.
Millions of people were heeding officials' advice and heading inland.
Death and devastation on Haiti
Rescue workers in Haiti tried to assess the extent of the damage caused by Matthew there, struggling to reach isolated towns. Some 30 deaths are attributed to the storms in the Caribbean in the past week, with at least 23 of them in Haiti.
A major bridge was washed out, cutting off southern Haiti, and roads were rendered impassable.
"The storm ripped off roofs, teared down electricity posts, a lot of people were looking for shelter in churches and schools," Doris Wasmeier, a German visitor in Port au Prince, told the DPA news agency.
"We don't know how the situation in the south is. Communication has broken down and the most important bridge came down. The region is totally cut off," said Wasmeier, who was an aid worker during the 2010 earthquake in Haiti.
After passing Haiti, Matthew barreled across part of Cuba before hitting the southern Bahamas.
cw, rc/kl (AFP, AP, dpa)