Ivan swirls through Caribbean
At least 11 dead after hurricane passes Jamaica
CNN's Karl Penhaul reports from Jamaica as Ivan pounds the island.
As of 11 p.m. Saturday ET
Position of center: 105 miles southeast of Grand Cayman
Latitude: 18.3 North
Longitude: 80.0 West
Top sustained winds: Near 165 mph
Source: Natl. Hurricane Center
(CNN) -- Hurricane Ivan has strengthened to a Category 5 storm after battering the island of Jamaica with heavy rain and strong winds, killing 11 people.
As of 11 p.m., Ivan's maximum sustained winds were near 165 mph (270 kph), with higher gusts, according to the National Hurricane Center in Miami, Florida.
Hurricane-force winds extended up to 70 miles (110 kilometers), while winds of tropical storm strength stretched 175 miles (280 kilometers).
The storm is expected to dump 8 to 12 inches of rain in its wake and bring storm surge floods of 5 to 8 feet above normal.
The storm is headed towards the Cayman islands, where the government is taking no chances. Airports have been closed and mass evacuations are in place.
The 45,000 people who live on the Caymans are "all hunkered down" and all but a few tourists flew home before the airports closed, government spokeswoman Patricia Ebanks said.
All 100 residents of Little Cayman flew to Grand Cayman, 90 miles away. Many of the 2,000 people on Cayman Brac are also in shelters on Grand Cayman, she said.
Ivan was expected to head for the western end of Cuba, including Havana, early on Monday.
Cuban President Fidel Castro appeared on television Saturday to warn residents to stock up on supplies and board up their homes.
With 2.5 million people living in dilapidated housing hardly improved and poorly maintained during the past 45 years, Havana may be the most vulnerable place in Cuba.
The government has ordered everyone living above the fourth floor of any building to move to a lower level. Buildings in Cuba have been known to collapse during thunderstorms.
Cubans have been unable to get plywood to board up windows. Even tape is hard to find.
Ivan has killed at least 11 people in Jamaica, officials with the country's Office of Disaster Preparedness and Emergency Management said Saturday.
Although most of the deaths were drownings in and around the Kingston area, at least one woman died when a tree crashed through her home in the capital, officials said.
One woman died in childbirth because the storm prevented her from reaching the hospital, an official said.
Some of the deaths were blamed on landslides, an official said.
Phone service was down for parts of Jamaica, and nearly 90 roads were blocked by landslides and flooding, which isolated Kingston, Prime Minister P.J. Patterson said.
Looting was a major problem on the island of 2.7 million, and the government imposed a dusk-to-dawn curfew in major cities. There were 12,000 people in more than 280 government shelters.
The hurricane center has downgraded the hurricane warning for Jamaica to a tropical storm warning.
A Category 5 hurricane has maximum sustained winds greater than 155 mph (249 kph). A tropical storm's winds range from 39-73 mph (62-117 kph).
The storm was also responsible for 17 deaths in Grenada, four in Venezuela and four in the Dominican Republic.
To the north in Florida, where two hurricanes have caused billions of dollars in damages in the past month, residents of the Florida Keys packed their cars and boarded up their homes Friday to escape Ivan.
Gov. Jeb Bush declared a state of emergency in advance of the storm, saying the state faces "yet another catastrophic disaster."
"This is time to prepare and not to panic," he told residents.
The latest forecast predicts the most likely U.S. landfall for Ivan's eye will be on Florida's panhandle, just south of Tallahassee, Tuesday night.
CNN's Karl Penhaul in Kingston and Lucia Newman in Havana contributed to this report.