[sdenton4]

According to the Ghostbusters, the Tunguska event was the biggest 'interdimensional cross-rip' of the 20th century, prior to the whole Zuul incursion.

[teddyh]

You mean the Gozer incursion. “Zuul was a minion of Gozer.”

[thesagan]

I really wonder which form the Destructor took in that scenario. The impact object itself?

[davesque]

This is my preferred explanation.