Florida's residents have begun to clear up the devastation left by Hurricane Wilma as it swept across the US state killing at least six people.
Some three million homes and businesses are without electricity and thousands of people remain in shelters.
Wilma made landfall as a Category Three storm with winds of 125mph (200km/h).
It is now moving up the US north-east coastline at 49mph (80km/h), bringing a threat of further flooding to areas already hit by heavy rains.
Wilma - the strongest hurricane to hit the Miami area since Andrew in 1992 - has already killed at least 17 people across the Caribbean.
Havana in Cuba has been flooded, while police in Mexico are trying to control looting in the aftermath of Wilma.
Meanwhile, the authorities in Haiti say Tropical Storm Alpha has left at least eight dead.
It is the first time the US National Hurricane Center has had to resort to the Greek alphabet to name a storm, after all 21 names pre-assigned for storms this year were used up.
'Driven by the devil'
Wilma made landfall near Naples in Florida at about 0630 (1030 GMT) on Monday, and moved north-east over Everglades City, bringing down power lines and trees, peeling off roofs and breaking water mains.
It then raced across the state, causing damage from Palm Beach to Miami, and as far south as Key West.
"It sounded like a freight train driven by the devil, that's what it sounded like," a resident in Miami said.
Officials blamed at least six deaths on Wilma, including a man who died after being pinned by a falling tree near Miami.
Bill Mauldin, police chief of Key West, the most southerly point in the US, said: "Many of the people that have been here for 25 or 30 years have told me in the last 24 hours that this is the worst they've ever seen."
President George W Bush has signed an order declaring Florida a major disaster area and releasing federal money.
The authorities have been distributing ice and water, but are waiting for more food to be delivered after the initial supplies ran out.
People are being warned it could take up to four weeks before electricity is fully restored. Insurers estimate the cost will run into billions of dollars.
By afternoon the storm had swirled into the Atlantic and had strengthened as it raced up the north-east coast.
The US national weather service has posted flood warnings in several areas, from New Jersey up to Maine. Many parts were saturated by heavy rains earlier in the month.
Wilma also forced 600,000 Cubans from coastal areas, where several villages were flooded by big storm surges.
Havana was hit by large waves, with water up to one metre high - penetrating four blocks into the city and flooding basement apartments.
Wilma finally left Mexico's Gulf coast on Sunday, after pounding the Yucatan peninsula, killing at least six people and destroying hotels and thousands of homes.
Police in the Mexican resort of Cancun fired shots to try to control hundreds of looters taking goods from damaged shops.
Tens of thousands of tourists have been stranded for up to five days in deteriorating conditions, often without running water or electricity.
Mexican President Vicente Fox has demanded the army and police set up a command centre to stop looting and help tourists in Cancun.