At least 14 people are now known to have died on the Caribbean island of St Lucia after Hurricane Tomas triggered landslides, officials say.
Tourism minister Allan Chastanet told local radio that the southern town of Soufriere had been worst hit and resembled "a war zone".
The storm, which struck at the weekend, also battered the island of St Vincent.
Tomas, now a tropical storm, is veering towards Haiti where thousands are still homeless after January's earthquake.
In St Lucia, Prime Minister Stephenson King declared a state of emergency and appealed for international assistance, local media reported.
Bridges were destroyed, and some of the worst-hit communities in the south could only be reached by boat.
"Recovery efforts are very slow. Our efforts to get help to the ravished community have been weakened as a string of fires in homes brings us to our knees," a firefighter in the capital Castries told the BBC.
He said the water mains were empty and that trying to get water to the fires "was an exercise in near futility" due to the mountainous landscape.
Tomas, downgraded from a hurricane on Sunday evening, lashed islands in the eastern Caribbean with sustained winds of 75mph (120km/h).
On Tuesday it was about 355 miles (570km) south of the Haitian capital Port-au-Prince and moving west at 12mph (19km/h) with sustained winds of 50mph (85km/h).
Forecasters have warned that Tomas could strengthen again to a hurricane and that parts of Haiti are in its projected path for later in the week.
"Right now they just need to stay tuned - this is the stage to be aware," said John Cangialosi at the US Hurricane Center in Miami.
UN humanitarian co-ordinator Nigel Fisher said relief workers in Haiti were trying to gather emergency shelter, water and sanitation supplies.
"We need as much of it as possible in place before Tomas hits," he said.
Imogen Wall, of the UN Office for the Co-ordination of Humanitarian Affairs, said warehouses in Haiti were being emptied of rope and tarpaulins to protect those in the camps.
The US Navy ship Iwo Jima is steaming toward Haiti to be on hand if emergency relief is needed, US officials said.