The sounds were tantalizing. Scratching and rhythmic tapping. And the farther rescuers descended into the wet muck, the louder they became.
Nearly four days after a mountainside collapsed and covered this farming village in up to 100 feet of mud, seismic sensors and sound-detection gear brought in by U.S. and Malaysian forces picked up what officials hoped were cries for help deep inside a buried elementary school.
"To me, that's more than enough reason to smile and be happy," South Leyte Gov. Rosette Lerias said Monday. "The adrenaline is high . . . now that we have seen increasing signs of life."
Still, it was hard to imagine there were survivors, and only bodies were recovered Monday. No one has been pulled out alive since just a few hours after the Friday morning landslide, which killed up to 1,000 people.
Philippine military officials had feared 1,800 people, virtually the entire population of Guinsaugon, died. But Gov. Lerias said Monday that 82 people were confirmed dead and 928 were missing.
Official figures of how many survivors were pulled from the mud Friday have also differed, with counts ranging from 20 to 57.
U.S. Marine Capt. Mark Paolicelli said Marines left the school site overnight because geologists warned them that heavy rains and danger of mudslides made the area unsafe.
"On some sides near the river, it's very moist, very soft soil," said Marine Capt. Burrell Parmer, "and you can get stuck up to . . . your waistline if you're not careful."
The search has focused on the school because of unconfirmed reports that some of the 250 to 300 children and teachers may have sent cell phone text messages to relatives soon after the disaster.
Under the glare of generator-powered lights, a multinational group of troops and technicians used high-tech gear like seismic sensors and sound- and heat-detection equipment alongside shovels and rescue dogs.
A U.S. military spokesman said late Monday that Marines digging at the site had found bodies, but no survivors.
"I asked had they received or found any type of survivors, and the answer was no," Parmer said after speaking to the commander of U.S. forces at the disaster site.
Some officials were talking about leaving the village as a massive cemetery, similar to tsunami-ravaged areas elsewhere in Southeast Asia where digging out bodies was simply too difficult and dangerous. With no one left to claim them, unidentified bodies already are being buried in mass graves.
"We will still search continuously, but we should be prepared that . . . you're going to have a mass grave right there," said Sen. Richard Gordon, chairman of the Philippine Red Cross. "How can you retrieve those who were buried so deep?"
On Monday, there was no visible sign of the school. Rescue workers were digging at two places - one where the school was believed to have sat close to the mountain, the other 200 yards down the hill, where the landslide could have carried it.
Dozens of U.S. Marines and Philippine soldiers, along with local miners, were digging in a watery, boulder-strewn spot around the school's original site, using shovels on the muck and moving it with body bags, while draining the murky water in large bottles.
The search was a painstaking process as the crews went yard by yard. At one of the highest points, local troops planted a Philippine flag.
The Marines deployed nine seismic sensors that can detect vibrations underground. With everyone standing still, one man then used a steel bar to hit on a rock several times and waited for any kind of response underground.
Four sensors detected some "noise" or vibration, but the men could not tell what it was.
"The farther down we went, the signals grew stronger," Marine Lt. Richard Neikirk said.
A Malaysian team, using sensor gear called Delsar and employing similar techniques, picked up noises, too.
"We have a sound," said Sahar Yunos of the Malaysia Disaster and Rescue Team. "Knocking, something like that."
The government had determined last May that St. Bernard, the township to which Guinsaugon belongs, was a danger zone, prone to natural disaster, and placed it on a geological hazard map. Fracturing volcanic rocks and weathering made the area "unstable and susceptible to mass movement," the environment department said in a statement over the weekend.
Policies were in place to avert a pending disaster: Area villages were evacuated late last year and a logging ban, to address the deforestation at the root of the problem, had been adopted more than a decade ago.
But almost immediately, residents trickled back, and the logging ban is widely seen as ineffective. Endemic corruption, lack of resources and weak law enforcement have allowed illegal logging to flourish and environmental predators to go unpunished, critics said.
Even as the rescue work continued Monday, political leaders were already issuing recriminations and demanding reform, noting that hundreds of thousands of Filipinos still living in more than 1,000 such danger zones remained at risk.
On Sunday, President Gloria Macapagal Arroyo called for action. "We should all join hands in the preservation of our environment and protect what is left behind for the sake of the generations to come," she said in a national address. On Monday, she ordered the release of money to upgrade the country's geohazard maps.
Information from the New York Times was used in this report.