More than 20 dead as a result of US snow storm

The unrelenting weather conditions in the United States have resulted in at least 21 deaths and left up to half a million homes without electricity, dpa reported.Among those killed in the winter weather was a pregnant woman struck by a snow plow in New York. The 36-year-old later succumbed to her injuries in hospital, while her son was delivered by caesarean section. He remains in critical condition.The other fatalities occurred as a result of traffic accidents, falling trees and heart attacks.On a highway around Philadelphia, Pennsylvania, 30 people were injured Friday morning in a large car pile-up involving up to 100 vehicles, a local ABC affiliate reported.The number of customers without power was at 525,273 early Friday, down from 625,000 on Thursday, CNN reported.The weather also took its toll on air travel. Thousands of flights were cancelled at several major airports on the east coast.The storm dropped up to 30 centimetres of snow fell on New York City. Mayor Bill de Blasio came under fire for keeping the city's public schools open on Thursday when the worst the the weather moved through.Many school districts in eight US states and Washington, DC, decided to keep their schools closed on Friday