Tsunamis are deadly and are quite capable of killing people. In Hilo, Hawaii, a particularly destructive series of waves killed 61 people who ignored tsunami warning. Never attempt to surf on a tsunami or approach within the reach of the waves.
Tsunamis are nearly impossible to predict. However, one indicator of tsunamis is earthquakes. Tsunamis do not always follow earthquakes, but it is a frequent occurrence, so those that live near the coast should be ready to evacuate the area immediately after an earthquake. This is extremely important as tsunamis that form near the coast can reach the shore in less than ten minutes.
One common misconception is that after the initial wave, it is safe to return to the coastline. A tsunami is not one wave - it is a series of waves. Do not return to the area until the entire tsunami has passed.
There are many technological methods of determining the approach of a tsunami, but nature has its own methods of warning people as well. If in a certain area, the coastal water is abnormally high or low, this is a warning for a tsunami.
For more information on tsunami safety, please visit the Pacific Tsunami Warning Center (http://www.prh.noaa.gov/pr/ptwc/).