The Tunguska event was a large explosion of between 3 and 50 megatons that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate, Russia, on the morning of 30 June 1908. The explosion over the sparsely populated East Siberian taiga felled a large number of trees, over an area of 2,150 km2 (830 sq mi) of forest, and eyewitness accounts suggest up to three people may have died. The explosion is attributed to a meteor air burst, the atmospheric explosion of a stony asteroid about 50–60 metres wide. The asteroid approached from the east-south-east, probably with a relatively high speed of about 27 km/s; 98,004 km/h (Mach 80). Though the incident is classified as an impact event, the object is thought to have exploded at an altitude of 5 to 10 kilometres rather than hitting the Earth's surface, leaving no impact crater.