Hurricane Sandy could cause record flooding and constitute a “life-threatening storm surge,” the National Hurricane Center said Sunday. In New York City, officials are taking extra precautions. Mayor Michael Bloomberg has ordered a mandatory evacaution of low-lying areas along the coast; the city's mass transit system will begin shutting down by 7 p.m. on Sunday; and schools will be closed on Monday. The storm is expected to make landfall Monday somewhere between the Delmarva Peninsula and Long Island. The director of the National Hurricane Center said millions of people could see river flooding or flash flooding as a result of the storm.