Not all tsunamis, however, can be predicted prior to reaching land. The 2004 Sumatra-Andaman tsunami is a good example of how fast. moving tsunamis can catch us off guard. This was the worst tsunami in recorded history, resulting in over 200.000 deaths Seismologists believe that an earthquake measuring 9.2 on the moment magnitude scale triggered the tsunami in the India and Ocean. This tsunami struck the coasts of Indonesia, Sri Lanka, India, and Thailand. waves up to 30 meters high destroyed everything in their path.