There has been some excellent documentaries on the History Channel, regarding earthquakes and tsunamis.
Check it out:
http://dsc.discovery.com/convergence/tsunami/tsunami.html
I am under the impression that the killer tsunamis are generated very far...thousands of miles away from where they make impact.
I have been looking at many documentaries on Earthquakes, volcanoes, and tsunamis.
Many single events have drastically changed Earth and civilizations.
Nobody, however, can predict when and where it will again happen.