Thousands of people were evacuated from Hatteras and Ocracoke Islands in North Carolina’s Outer Banks after a construction mishap damaged the area’s main power line, plunging the islands into darkness and shutting off air-conditioners.

The outage began early Thursday morning, and when it became clear power would not quickly be restored, county governments ordered nonresidents to evacuate the islands. The evacuation order for Ocracoke went into effect on Thursday night and the order for Hatteras on Saturday morning.

Since then, at least 3,782 people and 1,485 cars have left both islands, according to a news release by the office of Gov. Roy Cooper.

Those numbers probably understate the true extent of the exodus from the Outer Banks: While Ocracoke can be reached only by sea or by air, Hatteras is connected to the mainland, which means visitors can arrive — and evacuate — in their own cars.