http://english.aljazeera.net/watch_now/
8.8 magnetude earthquake hits the North-east. 4 Meter tsunami at the port of Kamaishi
Watching that tsunami destroy everything in its path is just frightening.
Speaking from experience, there are a few more factors to it. Mainly, where the epicenter is located. A shallow quake will create far more damage than one that may be bigger on the Richter scale even though it's smaller in magnitude.
Don't forget the materials of the buildings. Certain materials resonate more than others (brick = BAD).