Jamaicans headed inland and tourists fled the country as hurricane Dean headed for a direct hit on the island Sunday after a deadly and destructive march across the eastern Caribbean. Jamaica converted schools, churches and the indoor national sports arena into shelters and authorities urged people to take cover from a storm that could rake the country with winds of 145 mph and dump up to 20 inches of rain. "It's going to be very, very serious," said Lawrence Samuel as he shopped for emergency groceries while his wife and son went to the hardware store for plywood and other supplies. The National Hurricane Center in Miami said the first hurricane of the Atlantic season was projected to reach the most dangerous hurricane classification, Category 5, with winds of 160 mph before crashing into the Mexican coastline near Cancun on Monday night or Tuesday. The Mexican mainland or Texas could be hit later. Playing it safe, NASA shortened the last spacewalk for astronauts aboard the shuttle Endeavour and ordered the spacecraft to return to Earth on Tuesday - a day early - fearing the storm might threaten the Houston home of Mission Control. Jamaican Prime Minister Portia Simpson Miller said late Saturday the country was confronting a national emergency and urged people in flood-prone areas to head for shelter. "Do not wait for the last minute to make the decision to move from where you are," Simpson Miller said. "Decide now and begin to make arrangements to leave now." Thousands of alarmed tourists were not waiting. They jammed Caribbean airports for flights out of Hurricane Dean's path as the fierce storm that has claimed at least six lives. Jamaican officials closed the airports late Saturday ordered all businesses shuttered until Tuesday to prevent the looting that occurred during Hurricane Ivan in 2004. The first hurricane of the Atlantic season rolled through the Caribbean to the south of Hispaniola, the island shared by Haiti and the Dominican Republic, where heavy rain and surging seas caused flooding Saturday in coastal areas. In Gonave, an island with no electricity west of the Haitian capital, Port-au-Prince, thousands of people huddled in the darkness in churches and schools and other inland shelters as the storm brought heavy rain and fierce winds, said Samuel Menager, an employee of the international aid group World Vision who helped evacuate people from the coast. No deaths or injuries have been reported yet in Haiti, although authorities are surveying damages in the island's south, said Jean-Junior Joseph, former press secretary of the prime minister's office. The storm's wrath could be felt Saturday in Santo Domingo, the capital of the Dominican Republic, where a boy was pulled into the ocean and drowned while watching waves strike an oceanfront boulevard, the Dominican emergency operations center reported. Rough surf churned by Dean destroyed five houses and damaged 15 others along the Dominican coast, emergency officials said. People jammed supermarkets and hardware stores in Kingston to stock up on canned food, bottled water, flashlights, batteries, lamps and plywood. In malls in the Jamaican capital, storeowners hammered plywood over windows. Elaine Russell recalled Ivan's destruction three years ago. "I can't take it," she said. "The storm is bad enough but it's what happens afterwards - there's no light, no water." Farther west, the low-lying Cayman Islands were expected to take a direct hit on Monday. Tourists there jammed Owens International Airport in snaking lines that stretched outside onto a lawn. A police officer with a bullhorn kept order. Cayman Airways added 15 flights to Florida from the wealthy British territory, and they quickly sold out. The government ordered a mandatory evacuation by noon Sunday of Little Cayman, which is the smallest of the territory's three islands and has a population of about 150. Authorities in the eastern Caribbean were assessing the damage after Dean hit on Friday as a Category 2 storm with winds near 100 mph. On the island of Martinique, an overseas department of France, authorities on Saturday confirmed two deaths, including a woman who apparently fell and drowned in her home. Officials there estimated that $200 million to $270 million is needed to repair infrastructure. Agriculture Minister Louis Daniel Berthome said all banana crops were destroyed. In St. Lucia on Friday, strong winds tore corrugated metal roofs from dozens of homes and the pediatric ward of a hospital, whose patients had been evacuated hours earlier. Police spokeswoman Tamara Charles said a 62-year-old man drowned when he tried to retrieve a cow from a rain-swollen river. In Dominica, a woman and her 7-year-old son were killed when a rain-soaked hillside gave way and crushed the home where they were sleeping, said Cecil Shillingford, the national disaster coordinator. Dominica's government reported at least 150 homes were damaged. At 11 a.m. EDT the center of the storm was about 130 miles east-southeast of Kingston and expected to be very near Jamaica later in the day, with maximum sustained winds near 145 mph. Mexico's Yucatan issued a hurricane watch and Cuba issued a tropical storm warning and said it was evacuating 50,000 people from three central and eastern provinces.