The death toll in Haiti has risen to nearly 600 as rescue workers begin to reach remote regions hit by Hurricane Matthew.
Meanwhile in the US, more than 600,000 homes are without power with two million people urged to evacuate as the huge storm lashes the Florida coast.
Rescue workers and international aid agencies are working frantically in Haiti to clean up after the worst storm to hit the region in a decade that follows a devastating earthquake six years ago.
In the US, more than 4500 flight have been cancelled as the storm moves northwards towards South Carolina and Georgia.
Read more:
• Kiwis caught in Hurricane Matthew: 'Everybody's scared'
Earlier families who opted to stay put and wait it out told Brevard County Emergency Operations spokesman David Waters "we wish we hadn't stayed" in the area.
One family said the roof just "flew off their home" while others are being forced to wait until conditions improve and paramedics are able to reach them, he said.
On Friday afternoon the eyewall of the hurricane brushed the coast of Cape Canaveral bringing winds of up to 160km an hour.
The Category 3 storm saw panicked residents take to the shops to stockpile supplies, reinforce their homes or leave town following evacuation advice. An estimated two million people were warned to move inland before the hurricane hit.
Despite the very real threat the storm presents, Fox News weather presenter Shepard Smith was mocked for his report that warned people if they don't evacuate they will die.
In front of a huge graphic of the hurricane's projected path, he told the audience if "this moves 20 miles to the west and you and everyone you know are dead. All of you ... and your kids die too."
Dramatic footage from the National Oceanic and Atmospheric Administration showed a "Hurricane Hunters" crew flying blind into the eye of the storm in their WP-3D Orion as they attempt to gather information on the hurricane's path.
It shows a close-up look at the powerful storm as they navigate dense clouds and lightning to measure "steering currents" which provide specific information on the intensity and track the storm will take.
Up to 800 kilometres of coastline is expected to be smashed by howling winds and rain on Friday.
"Matthew is likely to produce devastating impacts," said Florida Governor Rick Scott before the storm hit
"The storm has already killed people. We should expect the same impact in Florida."
Matthew has been downgraded to a Category 3 but has already left hundreds of thousands of homes and businesses without power across the state.
South Carolina and Georgia are expected to be in the firing line this weekend.
Senior Hurricane Specialist Bryan Norcross warned Americans the storm could have catastrophic impacts and it would be like no other on the record books.
"We are concerned about reports of people staying in areas under mandatory evacuation areas," he said. "This is not hype, I am not kidding. Don't assume you will survive if you choose to stay."
On Friday the storm was expected to come dangerously close to shore west of Palm Beach and across Cape Canaveral and Jacksonville, according to the National Hurricane Center.
It could then move up to South Carolina before looping back toward Florida early next week as a tropical storm.
President Barack Obama declared a state of emergency for Florida, Georgia and South Carolina, freeing up federal money and personnel to protect lives and property.
Airports in Fort Lauderdale and Orlando closed with more than 4500 flights cancelled leading to disappointment for some tourists as famous theme parks Walt Disney World, Universal Studios and SeaWorld closed down.
Patients were moved out of hospitals and a nursing home while others took refuge in halls and high schools.
The co-ordinator for Haiti's Interior Ministry Emmanuel Pierre told The Associated Press late Thursday that he expects the toll to rise as authorities reach remote places that were left isolated by the storm.
Bodies have started to appear as waters recede in some areas two days after Matthew smashed concrete walls, flattened palm trees and tore roofs off homes.
In the Bahamas, authorities reported many downed trees and power lines but no immediate deaths.