Deadly Hurricane Dennis left behind a battered Cuba with shattered houses, shredded power lines and debris-littered streets on Saturday and reintensified over the warm Gulf of Mexico after a Caribbean rampage that killed at least 32 people. Dennis weakened as it crossed Cuba from a ferocious 150 mph_(240 kph) hurricane to a 90 mph (144 kph) storm, but immediately regained some of its lost strength when it hit open water and skirted Key West, the popular tourist island at the end of the Florida Keys chain, Reuters reported. The storm headed on a northwest track that threatened key oil and natural gas fields in the Gulf of Mexico, where a quarter of U.S. production comes from, and was expected to hit the U.S. mainland between the Florida panhandle and Mississippi on Sunday. Roaring winds with gusts of up to 100 mph (165 kph) and driving rain pounded blacked-out Havana all night. Authorities cut off power to avoid accidents from fallen cables. A weakened Dennis ploughed through the countryside just east of the capital city of 2 million, knocking down trees and power lines, but causing relatively minor damage. --More 1858 Local Time 1558 GMT