The collapse occurred overnight on November 8 on a section of the road running through Kim Dong Village, local authorities said on the morning of November 9.
Heavy rain caused a bridge approach on the Nghi Son - Bai Tranh route to collapse (Photo: Hoang Duong).
A Thanh Ky Commune official said authorities had redirected traffic and instructed vehicles to use alternative routes.
Heavy rain continued to affect the area on the morning of November 9. Rising water levels at Yen My Lake had also inundated several low-water crossings and local roads, temporarily cutting off access.
Most of the flooding was reported at crossings along local roads, while residential areas remained unaffected, the official said. Authorities were inspecting areas at risk of landslides and preparing response measures.
Three households living near Yen My Lake had been evacuated as a precaution.
The Thanh Hoa provincial hydrometeorological station forecast moderate to heavy rain across the province on November 9, with some areas likely to experience very heavy rain and thunderstorms.
The downpours could trigger flash floods and landslides in mountainous areas, as well as flooding in low-lying areas and residential neighbourhoods.
Rainfall in the coastal plains and the western and southwestern mountainous areas was forecast to reach 40-80mm, with isolated areas receiving more than 100mm. Other parts of the province were expected to record 30-60mm, locally exceeding 70mm.
Rainfall intensity could exceed 100mm in three hours, the station warned.
