[Verginius Rufus]

If the Tunguska object had reached earth a few hours earlier or later it might have taken out St. Petersburg, Russia, or Helsinki or Oslo or Whitehorse (Yukon Terr.). If St. Petersburg had disappeared the history of the 20th century would have been considerably different. Whitehorse, maybe not so much.

[Yosemitest]

"If St. Petersburg had disappeared ~ the history of the 20th century would have been considerably different. "

I'd agree.