Police investigating the deadly collapse of a retaining wall in Osan, Gyeonggi Province, have raided three locations, including Osan City Hall and the builder that made the wall.

According to the Gyeonggi Nambu Provincial Police Agency, investigators began the raid at 9 a.m. Tuesday at City Hall, Hyundai Engineering and Construction, and a construction supervision company. 

At City Hall, the investigators are searching the departments responsible for road maintenance and safety management. 

The police plan to secure construction and design documents to determine whether faulty construction was a factor. 

A ten-meter-high retaining wall along an overpass collapsed on Wednesday last week amid torrential rains, burying a car on the road below and killing one motorist.