What if the Perseid meteor shower dropped a big one, which struck the Earth?

If during the Perseid meteor shower one year a meteor the size of a 45ft motor coach made it to the ground, what would be the effect if it hit in some sparsely populated area like the American South West, the Serengeti, Siberia, etc? What would the effects be if it struck a deep body of water like the mid Pacific? How would the effects change if it where a shallower body of water like the Great Salt Lake, the Gul of Venezuela, the Gulf of Bothnia, etc? What would it be like of it hit a populated area like Bucharest, Chanchun, Patrai, or Rock Springs?