Authorities on Tuesday barricaded the area, while several units began to fix broken water pipes at Hoang Van Thu Street.
Heavy rains on Monday night felled several trees, electric poles, billboards and steelframes at a street section near the Phu Tai 2 apartment complex. The nearby pavements were also damaged in multiple sections, with certain sections eroded by as deep as 3-4 m underground.
The incident caused about 4,500 families to experience blackouts, and traffic was disrupted.
Locals said before the incident, the contractor of the apartment complex had dug into the ground near the sidewalks.
Hoang Anh Tuan, director of the Phu Tai real estate company, said the rain had damaged the drainage system underneath the sidewalks, causing damage outside the perimeters of the project, with the erosion eventually reaching inside.
Tran Viet Bao, director of the Department of Construction, said he had visited the site for an inspection. The initial cause was water seeping into two adjoined basements and bringing the surrounding soil down with it. As the old drainage system running along the pavements of Hoang Van Thu is located nearby, the problem quickly spread.
The construction department has requested the main investor to resolve the problem and re-evaluate its construction methods.
Authorities will re-route traffic and ban trucks in the area. By Wednesday afternoon, the Binh Dinh power company had restored electricity to all the affected families.