Last night, the category 4 storm with winds of up to 135mph was poised to strike the centre of Cuba, having already lashed part of its south-east coastline.
"It's right off the coast, they'll be getting hurricane-force winds before long if they haven't already," said Trisha Wallace, a meteorologist at the National Hurricane Centre in Miami. She said the hurricane was moving at around 12mph and that hurricane-force winds extended 50 miles from its centre with tropical storm force winds stretching another 140 miles.
Hurricane Dennis is the first of the season. Last year, catastrophic hurricanes - Frances, Ivan and Jeanne - ripped through the Caribbean with a ferocity not seen in years. Hundreds of people were killed in the islands and the storms left billions of dollars of damage in their wake, across the Caribbean and in Florida as well.
Forecasters yesterday predicted that the storm will intensify still further and hit the US anywhere from Florida to Louisiana by tomorrow or Monday. The Florida Keys were on hurricane warning and the rest of the peninsula on tropical storm alert.
Nasa decided to leave space shuttle Discovery on its launch pad at Cape Canaveral, Florida, but continued to watch Dennis closely. A decision to roll Discovery back to its hangar would delay the scheduled launch next Wednesday of the first shuttle mission since the Columbia disaster in 2003.
In past years Cuba, the largest and most populous of the Caribbean islands, has suffered relatively few hurricane fatalities. Experts said this was because the government usually evacuated people en masse - sometimes by force - as a precaution. On Thursday, more than 100,000 people were moved from the south-east of the island, civil defence officials said on state television.
Hundreds of tourists were taken to hotels in Havana and the northern Varadero beach resort while thousands of students at government boarding schools were sent home, and livestock was moved to higher ground. In contrast, officials in Jamaica and impoverished Haiti complained that few islanders heeded their warnings to get to higher ground.
In the south-western Haitian town of Grand Goave, an Associated Press reporter saw at least four people die when a wood and metal bridge collapsed.
Witnesses said the river suddenly came rushing over the bridge. In addition to the fatalities, the destruction of the bridge cut off Haiti's south-west peninsula from the rest of the country.
Elsewhere on the dangerously deforested island, wind gusts uprooted a palm tree and flung it into a mud hut, killing a fifth person, in the southern town of Les Cayes, the Red Cross said. Wind gusts ripped tin roofs from homes and whipped up sheets of rain that flooded roads.
In Jamaica, floods and debris blocked the road leading from the capital, Kingston, to the storm-battered east. A man there narrowly escaped from a car swept away by fast-flowing floodwater on Wednesday night, a day before the hurricane passed.
Hurricane Dennis has followed fast on the heels of Tropical Storm Cindy, which made landfall in the US in Louisiana on Thursday and disrupted oil production in the Gulf.Reuse content