
The bridge is on the road linking Tambon Nong Yat in Mueang district to Na Kae district.
Nakhon Phanom Highways Office director Wutthipong Khampusaen said a temporary Bailey bridge would be installed until the permanent structure can be repaired.
Na Kae district chief Metha Chujan said motorists are meanwhile being redirected to That Phanom-Na Kae Road.
Metha said the Kam River had overflowed its banks and inundated low-lying houses and farms in and around the villages of Pak Bang and Piman Tha, as well as urban Na Kae.