Authorities warned that the nation's biggest city could get hit with an 11-foot wall of water that could swamp parts of lower Manhattan, flood subway tunnels and cripple the network of electrical and communications lines that are vital to the nation's financial center.Sandy, a Category 1 hurricane with sustained winds of 75 mph as of Sunday evening, was blamed for 65 deaths in the Caribbean before it began churning up the Eastern Seaboard. As of 5 p.m., it was centered about 530 miles southeast of New York City, moving at 15 mph, with hurricane-force winds extending an incredible 175 miles from its center. It was expected to hook left toward the mid-Atlantic coast and come ashore late Monday or early Tuesday, most likely in New Jersey, colliding with a wintry storm moving in from the west and cold air streaming down from the Arctic. Forecasters said the combination could bring close to a foot of rain, a potentially lethal storm surge and punishing winds that could cause widespread power outages that last for days. The storm could also dump up to 2 feet of snow in Kentucky, North Carolina and West Virginia. Louis Uccellini, environmental prediction chief for the National Oceanic and Atmospheric Administration, told The Associated Press that given Sandy's east-to-west track into New Jersey, the worst of the storm surge could be just to the north, in New York City, on Long Island and in northern New Jersey. Forecasters said that because of giant waves and high tides made worse by a full moon, the metropolitan area of about 20 million people could get hit with an 11-foot wall of water. "This is the worst-case scenario," Uccellini said. New York Mayor Michael Bloomberg warned: "If you don't evacuate, you are not only endangering your life, you are also endangering the lives of the first responders who are going in to rescue you. This is a serious and dangerous storm."