Estimated to have been a 9 tonnes in size, a meteorite streaked across the sky over the Ural mountains in Russia and exploded at 30 to 50 kilometres above ground. The supersonic reentry injured an estimated 1100 people according to reports in Russia. Part of the meteor crashed into a frozen lake. An estimated 3000 buildings were damaged in the city of Chelyabinsk, including the roof collapsing at a zinc factory.