Record blizzards that dumped several feet of snow paralyzed much of the eastern United States, trapping millions in their homes and shutting down the federal government for a fourth day. Nearly 6,000 flights in airports between Washington and New York were canceled at the height of the storms Wednesday, stranding tens of thousands of passengers and hitting flights across the country, officials said. The latest snowfalls made the 2009-2010 winter the worst on record for the US capital. Conditions were so perilous that driving was banned for several hours in Baltimore. New York Mayor Michael Bloomberg ordered schools closed for a rare “snow day” and the United Nations headquarters closed, but the worst of the weather was in the Washington-Baltimore area, home to some eight million people. Residents had barely dug themselves out from an avalanche of weekend snow when fresh blizzards struck, this time with Arctic winds of up to 55 miles per hour that made even the shortest trip hazardous. “I urge all residents to heed the warnings of local officials and prioritize safety by staying off the roads unless absolutely necessary,” Department of Homeland Security chief Janet Napolitano said.One person was killed and another injured in a pile-up in central Pennsylvania, and several were injured in a 50-car pileup in Virginia, but most people avoided driving. “You will risk your life and, potentially, the lives of others if you get stuck on highways or any road,” warned Ed Rendell, governor of Pennsylvania state.