The labor ministry has assessed that Hyundai Development Company(HDC) is lacking overall in terms of on-site safety management.

The ministry made the assessment as it announced on Wednesday the results of its special probe on 12 large-scale construction sites operated by HDC, the developer of an apartment building in Gwangju that partially collapsed in January, killing six people.

The ministry said the investigation found 636 violations of the Occupational Safety and Health Act. The ministry said it took judicial action against 306 of the cases and slapped the company with roughly 840 million in fines for the remaining 330 cases.

The ministry said that of the total, 261 were violations of basic safety measures, such as installing safety railings to prevent deaths from falls while 144 were violations of basic obligations, including conducting hazard and operability studies and reporting industrial accidents.

The ministry said it is investigating the top safety and health managers of the 12 construction sites.