The continued lashing from slow-moving and deadly Hurricane Dorian made it difficult to know just how much flooding and destruction the storm had unleashed in the Bahamas, but officials on Monday began assessing the devastation amid fears of prolonged power outages, no access to clean water and a growing death toll.

On the Abaco Islands in the northern Bahamas, where Dorian made landfall Sunday as a Category 5 hurricane, as many as 13,000 homes were either damaged or destroyed, according to the International Committee of the Red Cross. At least five people were confirmed dead on Abaco, Bahamian Prime Minister Hubert Minnis said at a news conference Monday evening.

"It is clear that Hurricane Dorian has had a catastrophic impact," Sune Bulow, the committee's head of the emergency operation center, said in a statement. "We anticipate extensive shelter needs, alongside the need for short-term economic support, as well as for clean water and health assistance."

Joy Jibrilu, the director general of the Bahamas Ministry of Tourism and Aviation, echoed the need, telling MSNBC that about 80 percent of Abaco's more than 17,000 people were without homes.

"The infrastructure is totally underwater," Jibrilu said, adding, "The toll in terms of damage is going to be unprecedented."

The U.S. Coast Guard on Monday said more than 20 Coast Guard cutters crews from Miami and Key West were preparing to deploy to affected areas in the Bahamas and Florida.

Dorian was creeping westward Monday afternoon at just 1 mph. The storm's outer bands were beginning to rake South Florida, and mandatory evacuations were being imposed on U.S. coastal communities along the southeastern part of the country.

"To the residents of Florida, this storm is so strong that even if you're not in the direct path, the outer bands and the winds and the flooding and the sea surges — prepare for that," Jibrilu said.

Social media posts underscored the devastation as Dorian sat over the Bahamas for more than 24 hours, with maximum sustained winds topping out at 185 mph — an Atlantic hurricane record matched only by the Labor Day 1935 storm that struck the Florida Keys.

Hurricane Update: 20 feet of water. This a video sent to me from the home of Honorable Michael Pintard, Minister of Agriculture and Marine. This is his home on Grand Lucayan Waterway pic.twitter.com/MUNZDGZyae — Dem House Leader (@kionnemcghee) September 2, 2019

The winds ripped roofs off of homes, overturned cars and boats, and flattened trees and utility lines. In one video shared by Michael Pintard, the Bahamas' minister of agriculture, menacing waves could be seen slamming into the windows of his home, about 20 feet above the ground on Grand Bahama, the northernmost island in the archipelago.

In another video, a woman with a baby prayed for help, saying, "There's nowhere else to go."

Celebrity chef and restaurateur José Andrés told MSNBC from Nassau, the capital of the Bahamas, that he had food and supplies ready to bring to Grand Bahama and Abaco by midday Tuesday if helicopters and boats could reach them.

The prime minister said he worries that people had to climb to the roofs of their homes and may not have been able to get high enough to safety.

"We know that this was a bad hurricane dumping a lot of water, so we know that many of our people may have to run to ceilings and ... that poses another dilemma of having to exit the ceiling onto the roof," Minnis told NBC News. "You can imagine going on a roof under 200 mph wind."