Algodoo

The Tunguska Event, or Tunguska explosion, was a powerful explosion that occurred near the Tunguska River at around 7:14 a.m on June 30, 1908. The blast that occured when it exploded devastated an area of 830 sq. miles with three times he power of the most powerful nuclear bomb.

This is my representation of that event, with simplified forest and asteroid (it can go down to 1% realtime on a 4-core comp.!)
This uses scripting, and my computer will sometimes delete scripting after closing and restarting phun, so please tell me if it doesn't work.

DO NOT DOWNLOAD ON A SLOW COMPUTER!!!

There! I'm finished!