Tropical storm Gustav continued its destructive sweep across the Caribbean today, this time heading for Jamaica and the wealthy banking enclave of the Cayman Isles.
Its maximum winds were around 45 mph but it was forecast to regain strength and could become a hurricane again by tomorrow.
Oil workers began leaving rigs in the Gulf of Mexico and New Orleans prepared evacuation plans amid warnings the storm could hit the US coast as a major hurricane.
Gustav killed 15 people on Haiti's deforested southern peninsula, where it dumped 12 inches of rain. A landslide buried eight people, including a mother and six of her children, in the neighbouring Dominican Republic.
Gustav's expected track pointed directly at the Cayman Islands, an offshore banking centre where residents boarded up homes and stocked up on emergency supplies.
By Monday Gustav could make landfall anywhere from south Texas to the Florida panhandle, and hurricane experts said everyone in between should be concerned.
"We know it's going to head into the Gulf. After that, we're not sure," said meteorologist Rebecca Waddington at the National Hurricane Centre. "For that reason, everyone in the Gulf needs to be monitoring the storm."
New Orleans began planning a possible mandatory evacuation, hoping to prevent the chaos it saw after Hurricane Katrina struck three years ago tomorrow.
Shell said it was evacuating 300 people from rigs and other producers were doing the same. Transocean, the world's largest offshore drilling contractor, said all 11 of its Gulf rigs were pulling up and securing drill pipe and other underwater equipment as a precaution.
Gustav is particularly threatening because there are few surrounding wind currents capable of shearing off the top of the storm and diminishing its power, the hurricane centre said. "Combined with the deep warm waters, rapid intensification could occur in a couple of days."
The Cayman Islands ordered people to secure loose materials in their gardens to prevent them from becoming missiles in high winds, and told them to stock up on food, medicine and fuel for generators.
In the Haitian capital UN peacekeepers said they evacuated thousands by boat and truck, and were preparing to pull people out of the western town of Jeremie even as rain continued to fall.
In the Dominican Republic Marcelina Feliz and six of her seven children - ranging in age from 11 months to 15 years - were killed when a landslide crushed their tin-roofed house.
Feliz, 32, was found hugging the body of her smallest child.