A 40-meter section of National Highway 91 fell into the Hau River, a branch of the Mekong, on Wednesday morning.
The highway and the soil beneath in Binh My Commune in An Giang Province’s Chau Phu District slipped into the river after a crack opened up four days earlier.
There were no casualties but the crack is continuing to open up further, forcing authorities to evacuate dozens of households nearby.
Nguyen Van My, 70, who lives just across from the collapsed section, said the crack had kept widening in recent days until it reached 20-30 centimeters on Wednesday morning and the entire section broke away and fell into the river.
The collapsed section was around 10 meters wide, or more than one third of the highway’s width.