Leaders across much of the Caribbean are closing schools and government offices and urging people to stay home as Tropical Storm Isaac takes aim at the region.
In telling people to stay indoors, Dominica's prime minister said, "I don't want lives to be lost."
Puerto Rico's governor has declared a state of emergency and activated the National Guard. The U.S. Coast Guard ordered all commercial vessels bigger than 200 gross tons to leave the port or obtain permission to remain in port.
The Liat airline expects to cancel its Dominica flights by Wednesday afternoon, and American Eagle has already canceled its flights. The fast ferry that runs to Guadeloupe and Martinique will be stopped temporarily.
The storm is about 200 miles east of Guadeloupe with maximum sustained winds of 45 miles an hour. It's moving west at 19 miles an hour. The U.S. National Hurricane Center predicts it will be a hurricane by Thursday.