Hurricane Sandy rolled out of the Bahamas on Friday after causing 40 deaths across the Caribbean, churning toward the U.S. East Coast, where it threatens to join forces with winter weather fronts to create a devastating super storm.

The Category 1 hurricane toppled light posts, flooded roads and tore off tree branches as it charged through Cat Island and Eleuthera in the scattered archipelago, with authorities reporting one man killed, the British CEO of an investment bank.

People sit on the rooftop of houses submerged in floodwaters after days of heavy rain in Santo Domingo, Dominican Republic. (Ricardo Rojas/Reuters)

The death toll was still rising in impoverished Haiti, reaching 26 on Friday as word of disasters reached officials and rain continued to fall.

Joseph Edgard Celestin, a spokesman for Haiti's civil protection office, said some people died trying to cross storm-swollen rivers. While the storm's centre missed the country as it passed on Wednesday, Haiti's ramshackle housing and denuded hillsides make it especially vulnerable to flood damage.

Officials at a morgue in the western town of Grand Goave said a mudslide crashed through a wooden home on Thursday, killing 40-year-old Jacqueline Tatille and her four children, ranging in ages from five to 17.

"If the rain continues, for sure we'll have more people die," said morgue deputy Joseph Franck Laporte. "The earth cannot hold the rain."

Sandy was a Category 2 hurricane when it wreaked havoc in Cuba on Thursday, killing 11 people in eastern Santiago and Guantanamo provinces as its howling winds and rain destroyed thousands of houses and ripped off roofs. Authorities said it was Cuba's deadliest storm since July 2005, when category 5 Hurricane Dennis killed 16 people and caused $2.4 billion in damage.

Cuban authorities said the island's 11 dead included a four-month-old boy who was crushed when his home collapsed and an 84-year-old man in Santiago province. Near the city of Guantanamo, the Communist Party daily Granma reported, two men were killed by falling trees.

Official news media reported Friday that the storm caused 5,000 houses to at least partially collapse while ripping the roofs off 30,000 others. Banana, coffee, bean and sugar crops were damaged.

Sandy also killed a man in Jamaica on Wednesday when a boulder crashed through his house, and police in the Bahamas said a 66-year-old man died after falling from his roof in upscale Lyford Cay late Thursday while trying to repair a window shutter. Officials at Deltec Bank & Trust identified him as Timothy Fraser-Smith, who became CEO in June 2000.

One death was reported in Puerto Rico. Police said a man in his 50s was swept away Friday by a swollen river in the southern town of Juana Diaz, where rain from Sandy's outer bands has been steadily falling.

On Friday afternoon, the hurricane's centre was about 50 kilometres north-northeast of Great Abaco Island in the Bahamas and 695 kilometres south-southeast of Charleston, S.C. Sandy was moving north at 11 km/h with maximum sustained winds near 120 km/h.

Government officials in the Bahamas said the storm seems to have inflicted the greatest damage on Cat Island, which took a direct hit, and Exuma, where there were reports of downed trees, power lines and damage to homes.

"I hope that's it for the year," said Veronica Marshall, a 73-year-old hotel owner in Great Exuma. "I thought we would be going into the night, but around three o'clock it all died down. I was very happy about that."

On Long Island, farmers lost most of their crops and several roofs were torn off, said legislator Loretta Butler-Turner. The island is without power and many residents do not have access to fresh water, she said.

With the storm projected to hit the Atlantic coast early Tuesday, the U.S. National Oceanic and Atmospheric Administration warned it could merge with two other systems to become a hybrid, monster storm.

In the Bahamas, power was out on Acklins Island and most roads there were flooded, while on Ragged Island in the southern Bahamas, the lone school was flooded.

Russell, the emergency management official in Nassau, said docks on the western side of Great Inagua island had been destroyed and the roof of a government building was partially ripped off.

Jennifer Savoie, a New Orleans native who lives in Eleuthera, said that her fiance's resort, The Cove Eleuthera, was spared major damage but that power is out across most of the island.

"We know the protocol and how to prepare," she said. "It's in our blood. We were hit pretty hard though."

A resident salvages a refrigerator from his damaged house, with the help of other men, after Hurricane Sandy hit Santiago de Cuba on Thursday. Many homes were damaged or destroyed in the city of 500,000 people. (Miguel Rubiera/Cuban Government National Information Agency/Reuters)

There were no reports of injuries at the U.S. naval base at Guantanamo Bay in Cuba, but there were downed trees and power lines, said Kelly Wirfel, a base spokeswoman. Officials cancelled a military tribunal session scheduled for Thursday for the prisoner charged in the 2000 attack on the Navy destroyer USS Cole.

Officials reported flooding across Haiti, where many of the 370,000 people still displaced by the devastating 2010 earthquake scrambled for shelter. There are nearly 17,800 people in 131 temporary shelters, according to the Civil Protection Office.

The U.S. military will be moving ships from the Norfolk Naval Station region in Virginia out to sea to get out of the path of Hurricane Sandy.

The navy says 24 of the larger ships in southeastern Virginia bases, including the aircraft carrier USS Harry S. Truman, are preparing to leave and will be moving out over the next day or so.