<p><br /> A surprise pre-dawn coating of ice from freezing rain has sent cars and trucks sliding and led to a pile up of at least 31 vehicles on a major highway in the US Midwest.<br /> </p><p><br /> It took nearly five hours to clear an interstate highway in St. Louis, Missouri following a series of accidents in the area.<br /> </p><p><br /> The worst took place in the east bound lanes very early in the morning.<br /> </p><p><br /> Police said one person was critically injured and another 20 suffered minor injuries.<br /> </p><p><br /> At least one tractor-trailer was involved.<br /> </p><p><br /> The National Weather Service said sleet and freezing rain began moving through the area which caused dangerous driving conditions.<br /> </p>
