The latest major Atlantic hurricane of the season, Maria, has powered back to category five strength after pounding the Caribbean island of Dominica.
It weakened to a four after wreaking "widespread damage" on the island but is now packing maximum sustained winds of 265km/h.
The storm is moving along roughly the same track as Irma, this season's other category five hurricane.
At least one person was killed and two others are missing in Guadeloupe.
Local officials said one person was killed by a falling tree in the overseas French territory, while at least two more people were missing after their ship sank near Desirade, the easternmost island in the archipelago.
Heavy rainfall from Maria has begun lashing the Virgin Islands and Puerto Rico.
The governor of Puerto Rico, a US territory, has told the island's 3.5 million people to seek shelter.
Officials there fear the debris left by Irma earlier this month could now prove extremely dangerous in the winds of Maria.
The new storm is proving particularly treacherous as its strength can change dramatically in a matter of hours.
Photo caption: The waterfront in Fort-de-France, on the French Caribbean island of Martinique, was flooded by Hurricane Maria.