(CBS NEWS) - Vulnerable Haiti braced for flash floods, violent winds, and widespread destruction from the extremely dangerous Hurricane Matthew as the powerful storm approached the hemisphere’s poorest country Monday.

Already the director of Haiti’s Civil Protection Agency said two fishermen have died in rough water churned up by the approaching storm, hours before it was expected to make landfall. The deaths of the two fishermen in Haiti brings the total death toll from Hurricane Matthew to at least four.

The government banned boating along the country’s coastlines starting Saturday. But the head of an 80-member fishermen’s association in the south coast town of Gressier says some fishermen were taking to the seas early Monday.

Johnny Souffrant says “They feel they have to take risks to support their families.”

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The eye of the Category 4 hurricane, with maximum sustained winds of 130 mph, was expected to pass east of Jamaica and then over or close to the southwestern tip of Haiti late Monday or early Tuesday, the U.S. National Hurricane Center in Miami said. The strongest part of a hurricane is usually the northeastern quadrant, which is likely to pass right over the fragile island nation. The storm was also predicted to hit the lightly populated eastern tip of Cuba on Tuesday afternoon.

Forecasters said as much as 40 inches of rain could fall on some isolated areas of Haiti, raising fears of deadly mudslides and floods in the heavily deforested country where many families live in flimsy houses with corrugated metal roofs.

“Some of us will die but I pray it won’t be a lot,” said Serge Barionette in the southern town of Gressier, where a river recurrently bursts its banks during serious storms.

The U.S. State Department warned American citizens to leave both Haiti and the Bahamas in advance of the storm.

A hurricane warning was in effect for Haiti, Jamaica and parts of Cuba. Rain was already lashing parts of Jamaica and flooding streets and homes, but forecasters said the southern Haitian countryside around Jeremie and Les Cayes could see the worst of the rains and punishing winds.

“Wherever that center passes close to would see the worst winds and that’s what’s projected to happen for the western tip of Haiti,” said John Cangilosi, a hurricane specialist at the U.S. center. “There is a big concern for rains there and also a big concern for storm surge.”

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