Soviet Academy of Science 1927 expedition led by Leonid KulikTunguska 101th anniversary 30JUN09 Tomorrow, Tuesday June 30, 2009 marks the one-hundred-first anniversary of the Tunguska impact event in Russia of June 30, 1908. Wikipedia has a very good report on Tunguska:
... At around 7:17 a.m. local time,
Tungus natives and
Russian settlers in the hills northwest of
Lake Baikal observed a column of bluish light, nearly as bright as the
Sun, moving across the sky. About 10 minutes later, there was a flash and a sound similar to artillery fire. Eyewitnesses closer to the explosion reported the sound source moving east to north. The sounds were accompanied by a
shock wave that knocked people off their feet and broke windows hundreds of miles away. The majority of eyewitnesses reported only the sounds and the tremors, and not the sighting of the explosion. Eyewitness accounts differ as to the sequence of events and their overall duration. ... (more)
http://en.wikipedia.org/wiki/Tunguska_event