The Tunguska event was an aerial explosion that occurred at 60°55′ N 101°57′ E, near the Podkamennaya (Stony) Tunguska River in what is now Evenkia, Siberia, at 7:17 AM on June 30, 1908. Note that there is not any kind of crater.
Historical
Links: en.wikipedia.org, science.slashdot.org
By: Hinkkanen