SINGAPORE – The supervisor of a diver who was killed by a fallen structure that pinned him underwater at a jetty was sentenced to nine months’ jail.

Koh Chiew Tong, 49, pleaded guilty to one charge under the Workplace Safety and Health Act on Thursday.

He was employed by ship building and repair firm Marine Diving & Engineering for about 11 years and had been a diving supervisor for about nine years at the time of the incident.

Mr Muhammad Firdaus Jasni, 27, who was also working for the company, died of traumatic asphyxia with lung contusions after the 2018 incident on Pulau Sebarok, an island south of mainland Singapore.

Ministry of Manpower (MOM) prosecutor Delvinder Singh said that on July 23, 2017, a chemical tanker collided into a jetty at Pulau Sebarok and partially damaged it.

After the collision, the damaged section of the jetty had to be demolished and the underwater piles holding the jetty had to be fully extracted.

Marine Diving & Engineering was engaged to carry out underwater concrete pile cutting work, and Mr Firdaus was part of a dive team of eight that was tasked with removing the concrete piles. Koh was also a part of this dive team.

On June 23, 2018, Mr Firdaus was tasked by Koh to install brackets for cutting and lifting work on the piles.

After each pile was cut, the diver had to surface to the work barge. Koh was also supposed to ensure that all divers were out of the water before giving an all-clear signal for the pile to be lifted out of the water and onto a crane barge.

However, this was not complied with as Koh had instructed the divers to cut the piles without lifting them onto the crane barge, with the divers still diving and cutting other piles beside it.

Due to his instructions, two piles were not removed after they were cut and were left in a free-standing position without any support before preparation work to cut a third pile began.

These two piles suddenly collapsed and one of them struck Mr Firdaus, who was pinned down.

His co-diver, who saw the incident, went closer to the seabed and started feeling around for Mr Firdaus.

When he did not respond to nudges, the co-diver quickly surfaced to get help.

By the time Mr Firdaus was freed with help from the other divers, he was bleeding from his nose and ears and the right side of his face had turned blue black.

He was taken to the National University Hospital and died later that day.

The MOM prosecutor said Koh’s reckless act had resulted in the death of Mr Firdaus, adding: “At the worksite, as a diving supervisor, the accused was responsible to ensure that the dive team was safe when performing the work.”

However, Koh deviated from the guidelines, said the prosecutor.

Koh also did not ensure that there was no diver in the water after completing the pile cutting work, added Mr Singh.

The company was fined $200,000 on Oct 3, 2023, over safety lapses that led to the tragedy.

Anyone at work who, without reasonable cause, wilfully or recklessly does an act which endangers the safety of themselves or others can be fined up to $200,000, jailed up to two years, or both.