Tsunami is a natural disaster which involves a series of water waves caused by the displacement of a large water body like an ocean. Any disturbance above or below water like earthquakes can lead to tsunami. Tsunami also known as killer waves or harbor waves are very different from normal waves. Normal waves don't cause any destruction mostly. But tsunami causes extreme destruction because the wavelength of its waves are very high. Tsunami can be generated when the sea floor abruptly deforms and vertically displaces the overlying water.
Tsunamis cause damage by two mechanisms -- firstly because of the large volume of water it displaces and secondly because of the force with which the waves hit the living being. The attacks caused by tsunami inflict irreparable loss to many. It destroys many peoples' shelter and even kills many. The tsunami attack in the Indian Ocean in 2004 was a shocker.
Tsunami is a natural phenomenon. Hence it cannot be prevented, but the people can be protected from its effect.International and regional warning systems, especially for the Pacific Ocean, issue alerts before the big waves reach the shore. Ultimately we must understand that nature will let us live peacefully only if we respect nature.