Rescuers scoured the sea for missing tourists and soldiers raced to recover bodies amid fears of disease as Asia counted the cost on Monday of a tsunami that killed more than 16,400 along coasts from India to Indonesia. Relatives hunted through piles of dead stacked up in hospital corridors and threw flower petals into the waters off India to pray for the safe return of thousands still missing. Idyllic palm-fringed beaches across southern Asia were transformed into scenes of death and devastation by the waves unleashed from the world's biggest earthquake in 40 years that struck off the Indonesian island of Sumatra early on Sunday. International aid agencies rushed staff, equipment and money to the region, warning that bodies rotting in the water were already beginning to threaten the water supply for survivors. The wall of water up to 10 meters (33 ft) high flattened houses, hurled fishing boats onto coastal roads, sent cars spinning through swirling waters into hotel lobbies and sucked sunbathers, babies and fishermen off beaches and out to sea. Worst affected were Sri Lanka where 4,890 were killed, India where officials reported up to 5,700 dead, northern Indonesia with 4,500 drowned and Thailand's southern tourist isles and beaches where as many as 839 lost their lives. Some of the dead were foreign tourists. Of those 70 were in Sri Lanka and included at least nine Japanese who had been watching elephants in a park when the tsunami swept over them. "This may be the worst natural disaster in recent history because it is affecting so many heavily populated coastal areas ... so many vulnerable communities," U.N. Emergency Relief Coordinator Jan Egeland told CNN. The Geneva-based International Federation of Red Cross and Red Crescent Societies said it was seeking 7.5 million Swiss francs ($6.5 million) for emergency aid funding. "The scale of the tragedy is massive. Sri Lanka has never been hit by tidal waves or earthquakes or anything at all in its known history so this is a grave tragedy which we have not been prepared for," President Chandrika Kumaratunga told the BBC. Smaller tremors followed Sunday's earthquake, the world's biggest since 1964 and the fourth-largest since 1900.