BUXTON, N.C. (AP) — A monstrous Hurricane Irene tightened its aim on the Eastern Seaboard on Thursday, threatening 65 million people along a shore-hugging path from North Carolina to New England. One of the nation's top experts called it his “nightmare” scenario.The Category 3 storm with winds of 115 mph — the threshold for a major hurricane — would be the strongest to strike the East Coast in seven years, and people were already getting out of the way.Tens of thousands fled North Carolina beach towns, farmers pulled up their crops, and the Navy ordered ships to sea so they could endure the punishing wind and waves in open water.All eyes were on Irene's projected path, which showed it bringing misery to every city along the I-95 corridor, including Washington, New York and Boston. The former chief of the National Hurricane Center called it one of his three worst possible situations.“One of my greatest nightmares was having a major hurricane go up the whole Northeast Coast,” Max Mayfield, the center’s retired director, told The Associated Press.He said the damage will probably climb into billions of dollars: “This is going to have an impact on the United States economy.”Irene was expected to come ashore Saturday in North Carolina with 115 mph winds and a storm surge of 5 to 10 feet.