Hurricane Ivan tears into Cayman Islands and heads on towards Cuba

Hurrican Ivan barrelled into the Cayman Islands last night, its ferocious 155mph winds tearing off roofs while an 8ft storm surge flooded the coastal plain, including parts of the capital, George Town.

Hurrican Ivan barrelled into the Cayman Islands last night, its ferocious 155mph winds tearing off roofs while an 8ft storm surge flooded the coastal plain, including parts of the capital, George Town.

Details, including the precise path the hurricane was taking over the British territory, were sketchy and communication almost impossible as Ivan progressed across the Caribbean. Having wreaked havoc in Grenada and Jamaica, killing at least 56 people in the past few days, it was heading north for a direct hit on Cuba, expected some time today, and thence towards the Florida Panhandle, a strip of coastal land in the west of the state.

Ivan slammed either into or very near Grand Cayman at around noon local time yesterday following several hours of high winds that felled trees and knocked out power lines. "Oh my God, oh my God, the roof is coming off!" a woman at the Adams Guest House in George Town told a reporter shortly before the phone went dead.

A few minutes later, a firefighter was up to his knees in water somewhere in the capital. "We can't help anyone," he told the Miami Herald. "There's too much wind and water."

Although construction on the Caymans is more solid than on some of its impoverished neighbours, the three-island archipelago is low-lying and prone to flooding. Many of its 45,000 residents left late last week, flying to the United States or further afield. Almost all 150 inhabitants of Little Cayman were brought to the main island on Saturday. Special shelters on Grand Cayman offered room to 3,000 people. Others sought refuge in caves on Cayman Brac island, which have traditionally provided shelter from storms.

Ivan lost a little of its ferocity between Saturday and Sunday - the winds were 175mph at one stage - and was downgraded from a Category 5 to a Category 4 hurricane. Nowhere was more at risk than Cuba, where authorities have predicted a 25ft storm surge and a direct hit on the citrus fields of the Isle of Youth off the southern coast and the prized tobacco crop of Pinar del Rio province.

Buses, lorries and trains evacuated about 200,000 people from the most exposed coastal areas over the weekend, and as many as half a million people were believed to have moved out of Ivan's path. Thirty-foot waves were reported at some beaches. In the south-eastern province of Santiago de Cuba, some homes have reported damage, including two collapses on Saturday.

The government closed down sugar processing plants, set up food storage areas, cleared drainage canals and trimmed trees that pose a direct threat to populated areas. Along the south coast and on the Isle of Youth, residents frantically pulled television antennas off roofs, removed valuable guttering and tied down water tank lids as firmly as possible.

While officials issued upbeat statements about the resilience and solidarity of the Cubans - Fidel Castro himself told state television that the country was "prepared" - the precarious state of much of Cuba's housing stock and the lack of infrastructure was a cause of grave anxiety. "If God doesn't help us, I think this is going to be extremely tragic," 65-year-old Maria del Carmen Boza of Cojimar, a resort once frequented by Ernest Hemingway, told the Associated Press.

As many as 100,000 homes were feared to have roofs too weak to withstand hurricane-force winds. Some officials also voiced concern that densely populated, residential high-rise buildings could collapse. The economic impact on the island was also a worry. Citrus and tobacco together provide about $280m (£155m) in much-needed annual export revenue. The Cuban Weather Service's director, José Rubiera, warned that Ivan was "the strongest storm system to affect us in the entire revolutionary era'' - since Castro took power in 1959. That, in turn, raised questions about the possible political consequences of the storm.

Further north, meanwhile, the outlook was cautiously more optimistic. The best forecasts in Florida, still reeling from the devastation wrought by Hurricanes Charley and Frances, suggest that Ivan will not now hit the Keys or the rest of southern Florida but will rather veer to the west and head up towards the Panhandle. The storm might even skirt Florida and hit neighbouring Alabama instead.

Still, officials and residents of the Florida Keys were taking no chances. All weekend, a steady parade of cars made its way north. Florida International University in the Miami area offered its services as a shelter for hundreds of Keys residents. Others stayed with relatives or friends, or took a plane north.

In all, about half of the Keys' 80,000 residents were reported to have left. Officials strongly cautioned them not to return too soon.

"We have a very strong hurricane south of Cuba,'' said emergency management co-ordinator Billy Wagner. "We don't want anybody to drop their guard until we're in the clear and, right now, we're not."

WHY SO MANY STORMS?

What is a hurricane?

A hurricane is a tropical storm with a wind speed of 74mph or more. The most violent activity takes place in the "eyewall" - the area surrounding the eye.

Is the situation getting worse?

No former August has seen as many as three major hurricanes. And with eight named tropical storms in August compared with an average of 4.2, activity this year has increased.

Is global warming to blame?

Hurricanes are partly powered by heat from the sea, so any rise in temperature (this year the Atlantic Ocean is warmer than average) threatens more activity.

Will we see more activity this year?

Experts predict September activity to be much higher than average and October activity to be below normal.

Why are US hurricanes becoming more of a disaster?

Increasing numbers of people are living along the high-risk coastlines, meaning greater disaster when hurricanes strike.