A construction worker died in an accident early yesterday morning at the Lentor MRT station worksite, one of the stations on the future Thomson-East Coast Line (TEL).
Work at the site has stopped to facilitate investigations into the incident - the third workplace fatality this year.
The 48-year-old Malaysian man fell from a raised working platform 2.5m above the ground while working in a tunnel that connects to the station.
The accident took place at 3.35am, and the man was unconscious after the fall. He was later pronounced dead by paramedics at 4.30am.
Before tragedy struck, four workers had been dismantling a man-lock chamber of a tunnel-boring machine following the completion of tunnelling works.
The Ministry of Manpower (MOM) said the chamber - which was being lowered using chain blocks - suddenly swung and hit the platform that one of the workers was standing on, causing him to fall from it.
Man-lock chambers, which can be pressurised and depressurised, allow workers to move into and exit the compressed air section of the tunnel.
Compressed air is used in the construction of a tunnel to prevent the entry of groundwater into it, according to a Workplace Safety and Health Council guidebook.
The Land Transport Authority (LTA) said it was "deeply saddened" by the accident, and that it is working with the contractor to assist the worker's family.
"Following the incident, LTA also imposed a safety timeout to review work processes and is assisting the MOM and the police in their investigations," the LTA added.
The Singapore Civil Defence Force said it was alerted to the accident, which happened in Ang Mo Kio Avenue 5, at about 4.10am.
When The Straits Times visited the worksite yesterday morning, work appeared to have stopped and day-shift staff were told to report for a safety briefing.
Workers told ST that the worker who fell had been on the night shift.
The design and construction of Lentor MRT station and its associated train tunnels is being undertaken by China Railway No. 5 Engineering, which was awarded the $247 million contract in 2013.
Lentor MRT station is an underground stop which is targeted to be completed in 2020, as part of the second phase of the TEL.
Based on MOM statistics, workplace deaths fell to 42 cases in 2017, from 66 the year before.
Deaths in the construction sector halved from 24 in 2016 to 12 last year.