The Labour Ministry has lodged a criminal suit against the contractor of the Red Line elevated rail project following last week's fatal accident that killed three workers.
The three were killed when a steel support structure fell off a pillar at a Red Line construction site near Wat Don Muang School on April 28. The construction is handled by Italian-Thai Development Plc (ITD).
Sumet Mahosot, director-general of the Department of Labour Protection and Welfare, said the ministry's safety inspectors had filed the suit against Italthai at Don Muang police station.
By law, the department is in charge of safeguarding workers' welfare and is legally empowered to file legal action against contractors.
There have so far been six similar incidents, which have claimed eight lives, related to the 21-billion-baht rail project.
Mr Sumet said the department wanted to pursue criminal liability, arguing the case should not be settled only through the company paying a fine.
ITD appeared to be careless, based on frequent similar accidents, he said.
The ministry's safety inspectors, meanwhile, would instruct the company to check and fix its equipment within 30 days to make sure it is in good working order, Mr Sumet said.
The inspectors, who have questioned representatives from the firm and examined evidence, found the employer committed breaches of safety regulations, which resulted in the death of the three workers, he said.
ITD, according to the inspectors, allowed the three to work on the steel support structure, which is moving machinery, and this violates safety regulations in which employers must ensure no one holds, stands or travels on machinery, Mr Sumet said.
The employer also failed to properly train its employees how to handle cranes or moving machinery, he said, adding that Italthai did not appoint or register enough construction safety inspectors.
ITD's executives could not be reached for comment.