Tunguska explosion
The Tunguska explosion was an explosion that occurred in 1908. It was caused by Nikola Tesla, working for the Assassins, who tried to destroy the Staff of Eden as a strike against the Templars.
Prelude
In 1905, the Templar Rasputin came into possession of the staff of Csar Nicholas II, a Piece of Eden. It was taken to a secret facility in central Russia, near the Tunguska river. The Staff was used as part of research into wave-generation technology. Several years before, the inventor Nikola Tesla had been discredited and nearly ruined by the Templars, namely J.P. Morgan and Thomas Edison.
The explosion
In the summer of 1908, members of the Assassin's Order contacted Tesla, offering a chance to get back at the Templars. Using his mastery of electricity and the Wardenclyffe Tower, Tesla broadcast destruction into the facility, creating one of the largest explosions in history [more than 2000 kilometres of forest were flattened]. This obliterated the research facility and presumably the Staff.
Aftermath
The explosion was a complete Assassin victory. The Templars had not discovered the complete truth about the explosion until 2012, as one e-mail attests.