Hurricane Sandy, a late-season Atlantic cyclone that threatens to be one of the worst storms to hit the US northeast in decades, is slowly moved northward after killing at least 41 people in the Caribbean.

Sandy left a trail of destruction in the Caribbean, bringing strong winds and heavy rain. In Haiti, a bridge connecting to the Dominican Republic was destroyed by fast rising water.

Towns are flooded and residents have taken to higher ground for safety.

Forecasters said wind damage, widespread and extended power outages, and coastal and inland flooding were expected across the densely populated US East Coast when Sandy comes ashore early next week.

Forecast models show it will have all the ingredients, elements of a tropical cyclone and a winter storm, to morph into a massive and potentially catastrophic "super storm".

On its current projected track, government forecasters said, Sandy could make landfall on Monday night or Tuesday in Maryland, Delaware, New Jersey, New York or southern New England.

The US navy has already ordered some of its ships out to sea.

Al Jazeera's Iain Bruce reports.