Vietnamese state broadcaster VTV said the torrent of water gushing down from a mountain in Lao Cai province Tuesday buried Lang Nu hamlet with 35 families in mud and debris, AP reported.
Only about a dozen are known so far to have survived. Rescuers have recovered 16 bodies and are continuing the search for about 40 others.
The death toll from Typhoon Yagi and its aftermath has climbed to 141 as 69 others remain missing and hundreds were injured, VTV said.
Yagi was the strongest typhoon to hit the Southeast Asian country in decades. It made landfall Saturday with winds of up to 149 kph (92 mph) and despite weakening on Sunday, downpours have continued and rivers remain dangerously high.
Floods and landslides have caused most of the deaths, many of which have come in the northwestern Lao Cai province, bordering China, where Lang Nu is located.