[Dennis M.]

The Tunguska comet in 1908 is estimated to have been a little bigger and mostly composed of water. It would be a very big event, kind of like a small atomic bomb.

[MMaschin]

Tunguska caused more damage because it exploded in the atmosphere. A solid object of the same mass hitting the earth would cause much less damage.

If you consider the small odds of it hitting Earth, there is a very small chance that it would hit somewhere where the damage would be measurable. Yes if it hit in downtown Manhattan it would cause major damage, but there is a 99.99% chance it would not hit an urban area.