Hyundai Development Company Chairman Chung Mong-gyu stepped down Monday, apologizing for two fatal accidents at the builder‘s construction sites in Gwangju. 

“I apologize deeply to the family members of the victims in the accident in Gwangju and to the public,” he said during a press conference at its headquarters in Yongsan, Seoul. 

“I promise to give all effort and support to amend the situation at the accident site and regain public trust.”

The HDC chief said the legal period of safety guarantees on all HDC buildings would be extended from the current 10 years to 30 years, to protect customers from losses in the value of their assets caused by safety issues. 

External professionals on construction safety will be invited to conduct safety checks all HDC construction sites “to cut off distrust and worries.”

Construction on the site has been halted. Chung said reconstruction from scratch was an option, but the rescue operation and investigation into to the exact cause of the collapse would come first.

On Jan. 11, floor slabs and exterior walls of a 39-story apartment building in Hwajung-dong in Gwangju crumbled during construction, leaving five people still missing. It was the second safety accident involving HDC. In June, a five-story building fell into the road during demolition work for an HDC redevelopment project, leaving nine dead and eight injured.

Though stepping down from the chairman post, Chung said he would remain as the company‘s major shareholder. A second-generation member of the Hyundai Group family, Chung owns a 33.68 percent stake in HDC Holdings Co., which controls HDC Hyundai Development Co. as well as chemical and retail affiliates.

As the eldest son of Chung Se-yung, who is the third brother of Hyundai Group founder Chung Ju-yung, he led Hyundai Motor Group for three years until 1998, but left the carmaker after his cousin, former Chairman Chung Mong-koo, took over the automobile business.

“Since the appointment as HDC chief after moving from Hyundai Motor Group, I put all my effort for the development of HDC for 23 years and tried to protect public trust. It hurts to see such effort came to naught after a series of accidents. And with moral responsibility, I’ll step down from my post at HDC from this moment,” Chung said.

With two major accidents occurring in the same city in less than a year, the country’s ninth builder in terms of construction capacity has been facing public criticisms over its loose safety check and poor practices. 

Market insiders said HDC is likely to suffer financially, as the accidents could entail compensation for residents and cause the company to lose construction contracts in the future. Last week, Gwangju’s mayor said the city government would review legal measures to stop HDC from participating in construction projects in the city.

According to the Land Ministry, a 10-member committee will investigate the case for two months once the rescue operation for five missing people completes. 

On the same day of the Gwangju collapse, the National Assembly passed a revision to the Construction Materials Management Act to penalize companies for breaches of safety caused by their contractors. The HDC case in Gwangju, however, is not subject to a reinforced law on safety at construction sites, which is to take effect on Jan. 27.

In Korea, major construction projects usually involve subcontractors. For accidents at building sites, the people held responsible for safety accidents are usually onsite leaders, not executives. In the June collapse, eight of nine people indicted for negligence of duty were from subcontracted companies.

Meanwhile, HDC Holdings bought 103,407 shares in HDC after the accident over the three days from Jan. 13-17, in what appears to be an effort to prevent stocks from declining further. 

M&Q Investment and Partners, wholly owned by HDC Chairman Chung Mong-gyu, also bought 329,008 shares in HDC.

Shares traded at 18,750 won ($15.70) at the end of trading Monday, but had traded at 25,750 won immediately before the collapse on Jan. 11.