Strong winds and surf buffeted the U.S. detention camp for terror suspects at Guantanamo Bay, on the island's eastern end, where a guard tower was washed into the sea. There were no reports of casualties.
"It's arrived, with all its diabolical force," President Fidel Castro said on state television. He said 10 people died in southeastern Cuba, including one child who fell into roiling waters its mother tried to cross an old bridge.
An evacuation order was in effect in the Florida Keys, where officials feared Dennis could hit the island chain over the weekend on its way to the Gulf of Mexico, where CBS News correspondent
Brian Andrews of CBS Station WFOR-TV in Miami reports that 45,000 people have left the keys so far and the last flights left earlier Friday.
Although some have stayed behind, Andrews added that hospitals have been shut down to reiterate to residents that it is a very dangerous storm even as it likely passes to the west of the islands.
The storm's center made landfall on central Cuba's southern coast in the early afternoon.
The storm had strengthened Friday morning to a Category 4 with winds reaching 150 mph but had weakened by evening, though its winds were at a still potent 125 mph. It was the earliest Category 4 hurricane on record in the Caribbean, according to Colin McAdie, a meteorologist with the National Hurricane Center in Miami.
The center was near the central city of Colon late Friday, about 65 miles east-southeast of Havana and about 130 miles south-southeast of Key West.
CBS News Producer Portia Siegelbaum in Cuba reports that over a million and a half people had been evacuated from the country. She reports of 11 deaths so far.
Castro said there had been eight deaths in Granma Province, eastern Cuba of which two were women whose roof collapsed on them and one was a girl hit by a falling palm. Two other deaths he announced were in Santiago de Cuba, also in eastern Cuba. A mother was crossing a bridge with her two children and one slipped and went over the side.
Siegelbaum also reports of witnessing another death in Havana when a man went fishing on the rocks off of Havana's seafront drive and was swept off by the waves and drowned.
Hours before Cuba, Dennis struck Haiti and killed five people as it collapsed bridges, triggered landslides, inundated homes and blocked roads with downed power lines and trees.
In Jamaica, a rescue helicopter was to airlift food and emergency supplies to hundreds of stranded islanders in at least seven eastern towns cut off by knee-deep floodwaters, said Nadene Newsome, spokeswoman for the country's emergency management office.
"Flooding has affected every parish of the island and it will increase as long as the rain continues throughout the day" Friday, she said.
Although Dennis was losing some strength as it passed over Cuba, it was expected to remain a major hurricane as it emerged over the Florida Straits and into the southeastern Gulf of Mexico later Friday evening.