Hurricane Emily (search) pounded Grenada (search) Thursday, tearing the roofs off hospitals and other buildings, destroying crops and causing widespread flooding.

The storm, which strengthened to a Category 2 hurricane as it moved across the Windward Islands, packed sustained winds of nearly 100 mph and headed west at about 18 mph. At 11 a.m. EDT, it was about 560 miles southeast of Santo Domingo in the Dominican Republic and was predicted to strengthen over the next 24 hours.

Emily struck hard in Grenada, especially in the two northern parishes, St. Patrick's and St. Andrew's, and the outlying islands of Carriacou and Petite Martinique, authorities said. The damage comes as the island nation is still recovering from last year's devastating Hurricane Ivan (search).

"Serious damage has been inflicted on many parts of the island," said Rawle Titus, a spokesman for the National Disaster Management Agency.

In the capital, St. George's, winds tore the roof from the operating room of a new hospital built with help from the Cuban government. On Carriacou, the storm destroyed the entire roof of the only hospital, forcing the evacuation of patients, officials said.

Elsewhere in the former British colony, two police stations and two homes for the elderly also lost their roofs, homes were damaged, streets were flooded and crops were destroyed. Authorities asked the public to remain at home or in shelters, where more than 1,600 people took refuge, as they assessed the damage.

In Trinidad, there was widespread flooding and at least one house was washed away in the eastern community of Arima.

Tropical storm warnings also were issued for the islands of Bonaire, Curacao and Aruba and for part of Venezuela's northern coast.

Venezuelan authorities temporarily ordered some oil tankers and other ships to stay in port Thursday as the storm unleashed heavy surf and rains.

"We are still under emergency status even though the hurricane has changed its course and is getting farther away from Venezuela's eastern coast," port captain Jose Jimenez Quintero said. He said officials would soon re-evaluate the situation to determine whether to lift restrictions on boat traffic.

Grenada's Prime Minister Keith Mitchell had sought before the storm to reassure citizens that the government would not be caught off-guard — as it was when Ivan killed 39 people and left a wasteland of ruined buildings in September.

Grenadians rushed home under heavy rain, forming traffic jams in the capital. Islanders had flocked to the stores Tuesday, snapping up canned food, water and batteries. The rush contrasted with the attitude before Ivan, when islanders took few precautions.

"We took this very, very seriously," said Colin Dowe, an assistant dean at the island's St. George's University, where dozens of students and faculty members waited out the storm. "Ivan was much stronger so the general feeling is that we can get through this."

The struggle to recover from Ivan has prevented Grenada from thoroughly preparing for this year's hurricane season. Amid a shortage of construction supplies, many islanders still have no roofs and some children are still taught under tarps. Ivan's destruction left few buildings viable as shelters.

Emily trails Hurricane Dennis (search), which destroyed crops and killed at least 25 people in Haiti and 16 in Cuba last week.