Hurricane Ivan pummeled the Cayman Islands with fierce winds that ripped off roofs and floodwaters that swamped homes, then strengthened to an extremely dangerous Category 5 storm as it headed for western Cuba on Monday. The hurricane, one of the strongest on record to hit the region, has killed at least 65 people across the Caribbean and threatens millions more people in its projected path. About 1.3 million Cubans were evacuated from their homes, most taking refuge in the sturdier homes of relatives, co-workers or neighbors.