Hurricane Gonzalo struck Bermuda as a strong category two storm, the US National Hurricane Center said.
At 0000 GMT Saturday, the northern portion of the eye of Gonzalo, packing "damaging winds and life-threatening storm surges," moved over the island, the Miami-based center reported.
The storm had maximum sustained winds of 110 miles (175 kilometers) per hour, and was moving northeast at 16 miles (26 kilometers) per hour.
Gonzalo has already killed one person in the Caribbean and triggered a hurricane warning in Bermuda, a British overseas territory that is home to around 60,000 people.
The NHC said flooding was expected over much of the island from heavy rainfall and surges that already affected parts of the Virgin Islands, the northern coasts of Puerto Rico and the Dominican Republic, portions of the Bahamas, as well as the southeastern coast of the United States.