As the US East Coast digs out from record back- to-back blizzards, local governments today were tackling the mammoth clean-up, helped by sunny weather and above-freezing temperatures, according to dpa. Rescue workers in Maryland and Pennsylvania were using helicopters and forging through metre-high snow drifts trying to reach dozens of people stranded in cars and trucks during the blizzard on Wednesday. The storm crept out of Washington by Wednesday night, spreading 25 to 50 centimetres of snow as it pushed up the East Coast through New York City and Connecticut and then out to sea. It shuttered the federal government for an unprecedented fourth day Thursday, crippled local transport systems in Washington, Baltimore and Philadelphia and hamstrung air transport. More than 50 million people were digging out, shovelling snow, balancing on ice- covered sidewalks, trying to get back to normal work days and coping with millions of home-bound school children. Airports in Washington, Baltimore, Philadelphia and Newark, New Jersey, resumed limited operations Thursday morning. Airlines indicated they would cancel more than 1,000 flights, after cancelling 5,700 flights on Wednesday, USA Today reported. The Washington Post reported that 20 people were stranded in cars along unploughed roads throughout Frederick County, about 60 kilometres north of Washington DC. They were in cell phone contact with rescue workers. A few of them were subsequently rescued, according to broadcaster NBC. In Pennsylvania, about 11,000 National Guard troops were helping state police reopen roads and reach stranded motorists, the Harrisburg Patriot News reported. About 170 drivers were stranded between Harrisburg and Philadelphia Wednesday behind jack-knifed tractor-trailers. There were few deaths during the storms, as most residents heeded official warnings to stay off the roads. Three fatalities were reported in Pennsylvania, including two people who died in a collision between a snowmobile and a car in Lancaster. There were deaths reported in the Washington region too. In addition, several people who lost electricity fell ill while trying to heat their homes with charcoal burners. The second US blizzard in five days walloped the region while it was still digging out from the first blizzard's 45 to 60 centimetres last weekend. A third storm was on the horizon for Monday and Tuesday with minor amounts of snowfall. The second storm, coming on top of near-record snowfall on Friday and Saturday, broke a 111-year-old record in Washington, pushing the season's snow accumulation to 141.2 centimetres. Fifteen-year-old records also fell in Philadelphia and Baltimore. Under a clear blue sky, giant front-end loaders were scooping snow onto two-metre-high piles. The blizzards turned places like suburban Maryland into giant igloos. Shoveled pathways end in ice walls created by snow ploughs on cross streets. Navigating anywhere on foot was like walking a maze. Government safety officials worried about the new weight of snow on already overburdened roofs. On Wednesday evening, the roof of a US Mint building near Landover, Maryland, collapsed, the Post reported. The Philadelphia region was struggling with about 165,000 power outages, while about 45,000 customers lost power in the Washington- Baltimore corridor, media reports said.