http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake#IndiaThe Andaman and Nicobar Islands, just north of the earthquake epicentre, have had the most casualties in India. The tsunami reached a height of 15 m in the southern Nicobar Islands. It is estimated that 7,000 have died on the islands, and a similar number missing. One fifth of the population of the Nicobar Islands is said to be dead, injured or missing Chowra Island in the Nicobars has lost 2/3 of its population of 1,500. Communications have been lost with the Nancowry group of islands, some of which have been completely submerged, with the total number of the population out of contact exceeding 18,000. The Indian Air Force base in Car Nicobar, near the epicentre, is reported to have been severely damaged
On mainland India, the entire eastern coast was affected, killing more than 5,000 and rendering thousands injured and/or homeless The death toll in Tamil Nadu, which was most affected, was above 3,200. Along the eastern coast, 487 were killed in Pondicherry and 89 in Andhra Pradesh. Kerala, located on the southern part of the western coast of India, was also affected with 174 deaths and thousands rendered homeless. Hundreds were feared missing (1,200 in Andhra Pradesh alone). Most of the people killed were fisherfolk who lived along the coast. Many fishermen both at home and at sea were missing.
In Tamil Nadu where the official toll was 3,200, mostly women and children, over 1,700 were killed in the Nagapattinam district alone, over 400 in the Cuddalore district, over 525 in the Kanyakumari district and over 200 in Chennai (formerly Madras) city. It was reported that survey and rescue helicopters could not even land in Nagapattinam and Cuddalore districts due to floods and rains.Those killed in Kanyakumari include pilgrims taking a holy dip in the sea. Of about 700 people trapped at the Vivekananda Memorial on an island off Kanyakumari, 650 were rescued while the search is on for others. In Chennai along the Marina Beach, people taking part in various sports activities (including children), and those who were having a morning walk along the beach, were washed away.
It being a Sunday, there were more people than usual on the beach. Some unconfirmed reports claim that at least 5,000 fishermen and their families may be missing just from the Marina Beach area. A large number of pilgrims celebrating Christmas at the Velankanni church were affected. Eyewitness reports suggest that at least 1,000 people were on the beach on that morning. Water also rushed into the nuclear reactor complex at Kalpakkam, which was then shut off. No damage or radiation leak was reported The Indian Army, Navy and Coast Guard were pressed into service for undertaking rescue operations and to air-drop food to the tsunami victims.