Police on Thursday raided the offices of Samsung Heavy Industries as part of their investigation into a crane collision that killed six people and injured 25 others at the company’s shipyard in Geoje, South Gyeongsang Province.

A total of 30 investigators searched offices inside the shipyard in Geoje and secured documents such as job sheets and safety education materials, police said.

Investigators said it will focus on whether the crane collision was caused by miscommunication between crane operators.

They are also looking into whether the company, an affilate of Samsung Electronics, complied with safety regulations and whether there were any mechanical defects in the structures.

The police had earlier vowed a thorough investigation of the cause of the incident, citing the gravity of the industrial accident and its casualties.

Two cranes collided at the shipyard on Monday, Labor Day, causing one, nearly 60 meters long and weighing 32 tons, to collapse. Five were killed at the scene, while another victim died in hospital. Of the 25 injured, two are said to remain in a critical condition.

“We will fully cooperate with the police investigation and finding the cause of the accident,” said Samsung Heavy Industries.

Park Dae-young, president and CEO of Samsung Heavy Industries, apologized and visited the Paik Hospital funeral hall Tuesday night.

By Kim Da-sol (ddd@heraldcorp.com)