The first aerial surveys of the region revealed huge swaths of land underwater and the crumbled rubble of homes torn apart by the wave. One lay tilted, resting on the edge of its red roof, with tires and slabs of concrete piled up on the surrounding sand.
Two days after a powerful earthquake triggered the wave, the casualty count was still rising as rescuers and disaster officials finally reached the Mentawai island chain, which was closest to the epicenter and the worst hit. Bad weather had kept them away.
President Susilo Bambang Yudhoyono cut short a state visit to Vietnam to deal with two major disasters that struck Indonesia in less than 24 hours. The country's most volatile volcano, Mount Merapi, 800 miles (1,300 kilometers) to the east, erupted at dusk Tuesday, sending up searing ash clouds and killing more than two dozen people.
"I want to make sure the emergency response has been running well," Yudhoyono, a former four-star general, told reporters in Hanoi. "I want to see for myself the condition of the victims."
On Wednesday evening, disaster official Ade Edward nearly doubled the earthquake and tsunami casualty estimates to 272 dead with 412 missing. He said the rescuers who landed Wednesday received new casualty reports from village chiefs.
Both the quake and the volcanic eruption fell along Indonesia's portion of the Pacific Ring of Fire, a series of fault lines that are prone to earthquakes and volcanic activity stretching from the Western Hemisphere through Japan and Southeast Asia.
Rough seas and bad weather have hampered tsunami relief operations, leaving islanders to fend for themselves. With not enough people to dig graves, corpses littered beaches and roads, according to district chief Edison Salelo Baja. Fisherman were scouring waters in search of survivors.
The first cargo plane loaded with 16 tons of tents, medicine, food and clothes arrived Wednesday afternoon, said Edward. Four helicopters also had landed in Sikakap, a town on North Pagai island, which will be the center of relief operations.
"Finally we have a break in the weather," he said, adding that he hoped search and rescue operations would finally pick up pace. "We have a chance now to look for the missing from the sky and also to survey the extent of the damage."
Disaster officials were still trying to reach more than a dozen villages on the Mentawais - a popular surfer's destination that is usually reachable only by a 12-hour boat ride.
But they were preparing for the worst Wednesday, with hundreds of body bags being sent to the area, said Mujiharto, who heads the Health Ministry's crisis center.
The 7.7-magnitude quake that struck late Monday just 13 miles (20 kilometers) beneath the ocean floor was followed by at least 14 aftershocks, the largest measuring 6.2. The fault line on Sumatra island's coast is the same one that caused the 2004 quake and monster Indian Ocean tsunami that killed 230,000 people in a dozen countries.
Those and other islets hit were part of the Mentawai island chain, 175 miles (280 kilometers) from Sumatra.
Eight Australian survivors and an American and a New Zealander arrived in the Sumatran city of Padang on Wednesday, telling of their harrowing encounter with the tsunami.
They said they were on the back deck of their anchored boat when the wall of water smashed them into a neighboring vessel, triggering a fire that quickly ripped through their cabin.
"They hit us directly in the side of the boat, piercing a fuel tank," said Daniel North, the American crew member. "Almost immediately, the captain gave the order to abandon ship and everyone got off the boat."
They clung to anything that floated as they washed in the wetlands and then climbed the highest trees they could find and waited for more than 90 minutes until they felt safe.
Edward, the disaster official, said crews from a tourist boat were found safe after more than 24 hours missing in the Indian Ocean, including up to nine foreigners.
Associated Press writers Niniek Karmini and Irwan Firdaus contributed to this report.