GALLE, Sri Lanka - Bodies washed up on tropical beaches and piled up in hospitals Monday, raising fears of disease across a 10-nation arc of destruction left by a monster earthquake and walls of water that killed more than 22,500 people.
Thousands were missing and millions homeless. Humanitarian agencies began what the United Nations said would become the biggest relief effort the world has ever seen.
The disaster could be the costliest in history as well, with "many billions of dollars" of damage, said U.N. Undersecretary Jan Egeland, who is in charge of emergency relief coordination. Hundreds of thousands have lost everything, and millions face a hazardous future because of polluted drinking water, a lack of sanitation and no health services, he said.
More than 12,500 people died in Sri Lanka, nearly 5,000 in Indonesia, and 4,000 in India. The International Red Cross, which reported 23,700 deaths, said it was concerned that diseases like malaria and cholera could add to the toll.
Late Monday, Indonesian Vice President Yusuf Kalla was quoted as saying he believed the toll in the country could be as high as 25,000, that would be 20,000 more deaths than confirmed there so far and push the overall death toll to 42,000.
"We don't have confirmed data, but I think between 21,000 and 25,000 people (have died), he said, according to the Antara state news agency.
Dazed tourists evacuated the popular island resorts of southern Thailand, where the Thai-American grandson of revered King Bhumibol Adulyadej was listed as one of more than 900 people dead. Scores more died in Malaysia, Myanmar, Bangladesh, the Maldives. The waves raced 2,800 miles across the Indian Ocean to Africa, killing hundreds of people in Somalia and three in the Seychelles.
Eight Americans were among the dead, and U.S. embassies in the region were trying to track down hundreds more who were unaccounted for.
Sunday's massive quake of 9.0 magnitude off the Indonesian island of Sumatra's northern tip sent 500-mph waves surging across the Indian Ocean and Bay of Bengal in the deadliest known tsunami since the one caused by the 1883 volcanic eruption at Krakatoa - located off Sumatra's southern tip - which killed an estimated 36,000 people.
A large proportion of southern Asia's dead were children - as many as half the victims in Sri Lanka, according to officials there. A bulldozer dug a mass grave in southern India for 150 young boys and girls, as their weeping parents looked on.
"Where are my children?" said 41-year-old Absah, as she searched for her 11 youngsters in Banda Aceh, the Indonesian city closest to Sunday's epicenter. "Where are they? Why did this happen to me? I've lost everything."
Officials in Thailand and Indonesia conceded that immediate public warnings of gigantic waves could have saved lives. The only known warning issued by Thai authorities reached resort operators when it was too late. The waves hit Sri Lanka and India more than two hours after the quake.
But governments insisted they couldn't have known the true danger because there is no international system in place to track tsunamis in the Indian Ocean, and they could not afford the sophisticated equipment to build one.
Australian Prime Minister John Howard said he would investigate what role his country could play in setting up an Indian Ocean warning system. The head of the British Commonwealth bloc of Britain and its former colonies called for talks on creating a global early warning system for tsunamis.
Egeland said the issue of creating a tsunami warning system would be taken up at the World Conference on Disaster Reduction in Kobe, Japan from Jan. 18-22.
For most people around the shores across the region, the only warning Sunday of the disaster came when shallow coastal waters disappeared, sucked away by the approaching tsunami, before returning as a massive wall of water. The waves wiped out villages, lifted cars and boats, yanked children from the arms of parents and swept away beachgoers, scuba divers and fishermen.
In a scene repeated across the region Monday, relatives wandered hallways lined with bodies, searching for loved ones at the hospital in Sri Lanka's southern town of Galle - one of the worst-affected areas of the hardest-hit nation. People lifted blankets and soaked clothes to look at faces in a stunned hush, broken only occasionally by wails of mourning.
A tractor brought in about 15 corpses of mostly women and children, some wrapped in white plastic sheets, while a Buddhist temple across the street tried to help people find their missing.
"The toll is increasing," said Brig. Daya Ratnayake, a military spokesman. "We are finding more bodies."
Indonesia and Sri Lanka had at least a million people each driven from their homes. Helicopters in India rushed medicine to stricken areas, while warships in Thailand steamed to island resorts to rescue survivors.
In Banda Aceh, capital of Aceh province at the northern tip of Sumatra, the streets were filled with overturned cars and the rotting corpses of adults and children. Shopping malls and office buildings lay in rubble, and thousands of homeless families huddled together in mosques and schools. The minaret of the city's 125-year-old mosque leaned precariously.
At least 3,000 people died in the city of 400,000, which was virtually unique in the region in that Banda Aceh was destroyed by the temblor rather than the floodwaters. Officials said Indonesia's death toll could double to 10,000 when the full devastation in Aceh province becomes known.
In Thailand, the government offered free flights for thousands of Western tourists desperate to leave the southern resorts ravaged by the tsunami. Chaos erupted at Phuket airport as hundreds of tourists, many bandaged and brought to the airport in ambulances, tried to board planes for Bangkok.
Bodies were pulled from roadsides, orchards and beaches at Khao Lak resort, where the Swedish tour operator Fritidsresor said 600 Swedes had not been accounted for.
Jimmy Gorman, 30, of Manchester, England, said he saw 15 bodies, including up to five children and a pregnant woman, on Phi Phi island, one of Thailand's most popular destinations for Westerners,
"Disaster. Flattened everything," Gorman said. "There's nothing left of it."
The United States dispatched disaster teams and prepared a $15 million aid package to the Asian countries, and the 25-nation European Union promised to quickly deliver $4 million. Japan, China and Russia were sending teams of experts.
Egeland said he expected hundreds of relief airplanes from two dozen countries within the next 48 hours.