Hurricane Wilma has started whipping the coast of Mexico, where thousands of people have fled to safety.
The storm has already knocked out power supplies and flooded deserted streets. Five cities in Mexico have declared a state of emergency and set up shelters.
The hurricane has been downgraded to category four - the strongest type is category five - but experts say it could gain strength again.
Wilma has already caused chaos in the Caribbean and is heading for Florida.
Heavy rains and mudslides caused by the hurricane have already killed at least 13 people, mostly in Haiti.
This year has seen one of the most destructive hurricane seasons.
Wilma is the 12th of the year, and only once since records began in 1851 have there been that many - in 1969.
Thousands of people have died in Central America already this month from landslides and floods following torrential rains brought by Hurricane Stan.
Hurricane Katrina caused devastation in Louisiana and Mississippi when it struck at the end of August.