Philippine rescuers struggled against mud, fatigue and the stench of death to help the survivors of devastating flash floods that killed more than 650 people.
As bodies washed out to sea began rising to the surface, mortuaries were overwhelmed and emergency teams struggled to find survivors in cloying mud around the major port cities of Cagayan de Oro and Iligan on Mindanao island.
Entire villages were swept away by floodwaters as residents, normally spared from typhoons that devastate other parts of the Philippines every year, slept in the early hours of Saturday despite storm warnings.
The Red Cross said that 652 people had been confirmed dead and another 808 were currently listed as missing.
"I'm out here retrieving bodies that are starting to rise to the surface," Benito Ramos, head of the national disaster council, told AFP by mobile phone from a rescue boat off Cagayan de Oro.
The United States offered assistance to its former colony as the Philippine government and the Red Cross appealed for help to feed, clothe and house more than 35,000 people huddled in evacuation centres.
A 20,000-strong military force normally involved in fighting Muslim insurgents in Mindanao was leading rescue and relief operations.
A 30-member military and police rescue team landed on Sunday in Bayug, a delta area near Iligan formerly home to a fishing community of up to 1,000 people, an AFP photographer saw.
The delta had been swept clean of most structures, leaving those left alive having to rebuild huts with scrap wood, and Lieutenant Colonel Efren Baluyot said only 43 people were known to have survived there.
Local freelance reporter Leonardo Vicente Corrales told AFP that rotting corpses were piling up unclaimed at mortuaries in Cagayan de Oro as overworked staff ran out of embalming fluid, coffins, and water to clean them.
"The bodies are decomposing too quickly because they are drowning victims - because there is muddy water in their bodies," he said.
One establishment, Somo Funeral Homes, turned away the bodies of two drowned children. "We are already swamped. We only have four embalmers," its owner Ryan Somo told an AFP reporter.
The mayor of Cagayan de Oro, Vicente Emano, said he expected the death toll to reach 500 just in his city, which has a population of half a million.
The local authorities opened up fire hydrants and long lines soon formed as residents queued for fresh water.
In the hamlet of Macasandig, near Cagayan de Oro, teacher's wife Divilita Cuartero, 38, said she saw two dead bodies among the wreckage of houses near her own home, which was filled with mud from the nearby Cagayan river.
"I'm thankful that we woke up in time and were able to run toward the road, otherwise we would be dead by now," the mother of one told AFP.
The Philippine National Red Cross listed 346 deaths in Cagayan de Oro and 206 in Iligan. Smaller tolls were reported in other parts of Mindanao and the central province of Negros Oriental.
Gwendolyn Pang, the organisation's secretary general, said the 808 people listed as missing could be trimmed as the dead were identified.
Authorities likened tropical storm Washi to Ketsana, one of the country's most devastating storms which dumped huge amounts of rain on Manila and other parts of the country in 2009, killing more than 460 people.
Philippine President Benigno Aquino has ordered a review of the country's disaster defences as it became apparent that residents were unprepared for such a deadly storm.
Ramos, the disaster agency chief, said the government faced a formidable task with 100,000 people needing help, including those who sought refuge at schools, government buildings and gyms.
The national government has begun airlifting mats, blankets and clothes to the affected populations of the south, he added.
Debris has to be cleared, electricity and drinking water have to be restored and damaged roads and bridges must be repaired, officials said.
US Secretary of State Hillary Clinton sent condolences to the Philippines and said in a statement: "The US government stands ready to assist Philippine authorities as they respond to this tragedy."