Galvanized by a potential natural disaster just over the horizon and rushing toward them, residents of Jamaica and the Cayman Islands fortified themselves Saturday for the unwelcome arrival of Hurricane Dean.
''Let us band together and unite in the threat of this hurricane,'' said Jamaican Prime Minister Portia Simpson-Miller, who ordered shelters opened across the island as watches and warnings were posted there and in the Caribbean.
Dean exploded into a Category 4 storm and it kept intensifying as it roared through the warm Caribbean, striking glancing -- but powerful -- blows at Puerto Rico and the Dominican Republic. At one point Saturday, its winds built to 150 mph.
By midday Saturday, its most powerful outer squalls approached the large island of Hispaniola, shared by the Dominican Republic and Haiti.
It central core was predicted to pass just south of Haiti late Saturday, with the rest of the billowing storm bringing up to six inches of torrential rain to that flood-prone country. As many as 20 inches could inundate parts of Jamaica.
''I'm a little panicky,'' said Kerns Olibrice, 28, who lives in the Port-au-Prince suburb of Kenscoff.
The core seemed certain to strike or come dangerously close to Jamaica and the tiny Caymans on Sunday and Monday. Then, Cancún, Cozumel and neighboring areas on Mexico's Yucatán Peninsula could be in grave danger.
''Dean could become a Category Five at any time before it reaches Yucatán,'' said hurricane specialist Lixion Avila of the National Hurricane Center in West Miami-Dade County.
Dean will pass well south of South Florida, though its secondary effects will elevate offshore seas through Monday and pump some rain and wind into the region.
The storm will reach the Gulf of Mexico next week -- and then strike the Gulf Coast, possibly near the Texas-Mexico border.
Texas Gov. Rick Perry declared the storm an ''imminent threat'' and NASA announced that it will bring shuttle Endeavour and its crew home a day early on Tuesday, in case Dean veers toward its control center in Houston.
As a Category 2 hurricane, Dean killed three people Friday in St. Lucia and Dominica. Then, it strengthened into a major Category 4 hurricane. By the time it reaches Jamaica, the Caymans and the Yucatán, it could approach or exceed Category 5 status, with winds above 155-mph.
''We are prepared for the worst,'' said Kerry-Ann Morris, a Jamaican spokeswoman.
Forecasters said she had good reason to be concerned.
Dean ripped through the outer arc of islands Friday morning, damaging homes, flooding streets and killing a 62-year-old man in St. Lucia and a woman and her 7-year-old son in Dominica, according to The Associated Press.
''We don't have a roof . . . everything is exposed,'' Josephine Marcelus, a resident of Morne Rouge, a town in northern Martinique, told the AP. ``We tried to save what we could.''
Dean's outer bands, filled with rain, were expected to sweep through mountainous areas of the Dominican Republic and Haiti Saturday, raising the possibility of flash floods and mudslides.
In 2004, floods and mudslides produced by a glancing blow from Hurricane Jeanne killed more than 3,000 Haitians.
On Friday, Haitian officials begged residents to prepare, especially those who live near rivers. They were advised to seek higher ground immediately.
Some said they would ignore the warnings. The reason: no means to leave.
''Tell me, where am I going to go?'' Wilden Pierre, 20, said outside his shed, a hodgepodge of tin perched over a riverbed in the hills above Port-au-Prince. ``I have no place to go -- I have no money.''
Dean appeared likely to just brush the Dominican Republic, but even a passing encounter with a storm this powerful can prove deadly and damaging.
Authorities warned residents to stay off beaches and advised those living in low-lying areas to remain alert.
Emergency managers opened 100 lines for calls and told coastal residents that they should stock up on food and water.
In the Santo Domingo neighborhood of La Javilla, residents kept a close eye on the nearby Ozama River, which floods after moderate rains, said Minerva Mendez Reyes, who owns a small grocery store.
Two weeks ago, a sudden storm inundated her neighborhood and soaked 100-pound bags of rice and sugar. ''Just about every week, we end up fighting with the water,'' she said.
Still, it seemed that Jamaica and the Caymans were most at risk.
In Jamaica, emergency managers positioned relief supplies and urged citizens to check their roofs, prune trees and otherwise begin preparing.
''Right now, everybody is on high alert,'' said Morris, the Jamaican spokeswoman with the Office of Disaster and Preparedness Emergency Mangement in Kingston.
Maybe so, but many residents were taking a wait-and-see attitude, especially in Kingston, where there was no rush to board up homes or crowd grocery stores or gasoline stations.
''I have to see it first before I believe in it,'' said Mitch Landell, 28, a street vendor across from the famed National Bakery on Half-Way Tree Road in Kingston.
In Montego Bay, however, more concern was evident. Officials evacuated tourists from waterfront hotels and asked airlines to add more outbound flights Saturday.
''I am scheduled to leave Jamaica on Sunday,'' said tourist Mike Wallace of Miami. ``But I don't know if this would be possible. I am just not sure what is going to happen.''
The Caymans were pummeled in 2004 by Hurricane Ivan, which destroyed or damaged countless homes and wrecked businesses, roads and utilities. The islands still haven't fully recovered, and now they might absorb another hit.
Cayman Airways and other carriers added flights Friday and hotels advised tourists to leave.
''We have a small window of opportunity in which visitors wishing to leave may do so,'' said Ebanks, the government spokeswoman.