MIAMI (Reuters) - Hurricane Katrina hammered Florida's crowded southeast coast with hours of buffeting winds and whipping rains, pitching 2 million people into darkness as power lines came down and killing two.

The storm, which was supposed to be a minimal hurricane but nevertheless delivered a fierce punch, weakened slightly over the swampy Everglades on Friday, but in its wake it left flooded neighborhoods and streets carpeted with tree limbs and leaves.

Katrina dumped up to 12 inches (30.5 cm) of rain after coming ashore just south of Fort Lauderdale and then began a slow and punishing trek southwest across southern Florida, said the U.S. National Hurricane Centre in Miami.

Two men were killed in Fort Lauderdale and the city of Plantation to the west by falling trees, said Broward County public information officer Dennis Myers. WFOR television said the first man died when the tree brought a power line down onto his car.

'This is going to be a long night for Miami-Dade and Broward counties,' hurricane centre director Max Mayfield told CNN.

While Katrina was expected to weaken over land, Mayfield warned it would restrengthen again once it emerged over warm Gulf of Mexico waters and could loop north to slam into the hurricane-scarred Florida Panhandle as a much more powerful hurricane. The area was hit in July by Hurricane Dennis and last September by Hurricane Ivan.

Florida Power and Light Co., the main electricity company in the area, said more than 1 million customers, representing more than 2 million people, were without power and that number was bound to rise.

Katrina made landfall at about 7 p.m. EDT (12:00 a.m. British time) on Thursday between Hallandale Beach and North Miami Beach with sustained winds of 80 mph (130 kph), the hurricane centre said. By early on Friday, as it moved west of Miami, the winds had eased to 75 mph, the centre said.