As Hurricane Irene caused wind and rain in North Carolina, more than 2 million people up and down the Eastern Seaboard were issued mandatory evacuation orders. “Don’t wait, don’t delay,” President Obama warned Friday afternoon as he ended his Martha’s Vineyard vacation early. New York took unprecedented measures to prepare by ordering mandatory evacuations of 300,000 people who live in the low-lying parts of the city, including Battery Park City, Coney Island, and the Rockaways, and shut down the mass-transit system. (See the evacuation-zone map here and here.) Parts of suburban Long Island were evacuated Friday and will be Saturday morning, as well as parts of coastal New Jersey. Atlantic City closed its casinos for only the third time in its history. It's estimated that Hurricane Irene will cost $20 billion in damages, meaning it would be the third-most-costly hurricane, behind only Hurricane Katrina and Hurricane Andrew. Track the storm here.