Typhoon Ketsana has cut a devastating swathe through Southeast Asia, leaving hundreds dead and millions more injured, homeless or lacking basic resources.

The trail of destruction began in the Philippines, which bore the brunt of the storm Saturday when a month’s worth of rain fell in just nine hours.

Described as the heaviest rainfall to hit the country in 40 years, Ketsana plunged 80 percent of the capital Manila under water. At least 246 people were killed, with a further 2.2 million directly affected. At least 375,000 people have been forced into evacuation camps, stretching the country’s emergency relief capabilities to their limits. By Sunday, wind speeds had reached 180 km/h and 48 centimetres of rain was recorded in a 24-hour period.

On Tuesday, Ketsana landed in Vietnam. More than 55 people died and a further 11 are still missing. Six coastal provinces were evacuated, an operation involving almost 170,000 people. The city of Hoi An, a UNESCO World Heritage site, remained under 3 metres of water Wednesday. Local officials compared it with a disaster that killed hundreds along the country’s central coast a decade ago.

World Vision reported that 5,800 houses had collapsed, with another 163,000 stripped of their roofs. Some 20,000 hectares of agricultural land have been flooded, according to government officials.

On Tuesday evening, the storm collided with Cambodia, killing at least 11 people and forcing thousands of families to flee their homes to escape the rising floodwaters.

By Wednesday, the typhoon had lost some of its strength and was downgraded to a tropical storm as it continued to push on into Laos. No deaths had been reported as of last night, but flooding had left some areas along the Sekong River awash in up to a metre of water. Two villages in Sekong province were completely submerged.