Tunguska

Tunguska is a remote, largely uninhabited region in Siberia, Russia, near a river of the same name. It is known for an enormous impact event about 7:17 AM local time, on the morning of June 30, 1908, which felled an estimated 60 million trees over 2,150 square kilometres but did not leave a crater. The impact was felt as far away as 1,000 kilometres. At 500 kilometres, witnesses had claimed to have heard a 'deafening bang' and a cloud on the horizon. The size of the blast is said to have been between 10 and 15 megatons of TNT.