WILMINGTON, N.C., Sept 14 (Reuters) - Hurricane Florence crashed into the Carolinas on Friday, knocking down trees and swamping streets with torrential rains and a powerful storm surge, before slowing to a pace that meant it would plague the area with days of flooding.The hurricane’s storm surge - the wall of water it pushed in from the Atlantic - had “overwhelmed” New Bern, a town of about 30,000 people at the confluence of the Neuse and Trent rivers, North Carolina Governor Roy Cooper said.“The sun rose this morning on an extremely dangerous situation and it’s going to get worse,” he said at a news conference in Raleigh.