A massive rescue effort got underway in the Bahamas as Hurricane Dorian moved on, leaving much of the Caribbean nation in rubble after having killed at least seven — with the death toll expected to rise.

Rescue crews fanned out across the Abaco Islands and Grand Bahama Island, the hardest hit by the storm, using surveillance aircraft in the air and jet skis, boats and bulldozers on the ground to find survivors amid a landscape of shattered homes and flooded streets.

Many of the areas remain out of reach of Bahamanian rescuers, as more than 600 police officers and marines moved into Grand Bahama and another 100 in Abaco.

“Right now there are just a lot of unknowns,” said Iram Lewis, a member of the commonwealth’s parliament. “We need help.”

Prime Minister Hubert Minnis called it “one of the greatest national crises in our country’s history.”

The Red Cross reported that 45 percent of the homes in Abaco were damaged or destroyed when Dorian hit the islands with 185-mph winds and gusts up to 225 mph Sunday.

Residents became trapped in their homes and attics as floodwaters rose as high as 23 feet.

The Tribune, the largest newspaper in the Bahamas, reported that the US Coast Guard and US border patrol agents had airlifted 61 people from Grand Bahama Island.

With the rain subsiding and the storm clearing the island Wednesday, rescuers are now hoping to rescue those who survived and assess the full impact of the storm.

Speaking from the Oval Office, President Donald Trump said the US is also providing unspecified humanitarian assistance to the Bahamas, which he said had been hit like “few have ever seen before.”