Silly rabbitts
Tunguska was the crash of the Zorgon Death Fleet when they re-entered
normal space too close to our planet.
We were very lucky - this time....
I remember when some scientists tried to blame the Big T on a mini black
hole smashing through Earth, circa 1973. Whatever is in vogue at the time
someone suggests something new for the explosion.
It was probably a comet that hit us by chance. Boring but far more plausible.