SINGAPORE, July 14 — The Land Transport Authority (LTA) has ordered a "safety timeout” for all road and rail construction sites this morning, hours after one worker was killed and 10 others injured by the partial collapse of a highway structure under construction at Upper Changi Road East.

The Building and Construction Authority (BCA) has also revoked the permit for construction works and is investigating the cause of the incident.

"The rest of the constructed viaducts are not above any public roads and will not pose a risk to the public,” BCA said in a statement today, adding that as a safety precaution, the adjacent girders will be propped and supported.

Recovery works for the affected slip-road from Upper Changi Road East to PIE (Changi) are estimated to take about two days, before it can be re-opened for traffic. In the meantime, LTA said it has begun constructing a temporary bypass road to facilitate access for motorists coming from the east along Upper Changi Road East and wanting to get onto PIE (Changi), which will open by tomorrow morning.

More buses on Service 24 route, which has been affected by the slip road closure, have also been added.

The incident took place at about 3.30am, at a worksite where a new road viaduct from the Tampines Expressway to the Pan Island Expressway (Westbound) is being constructed. A section of the viaduct structure between two piers collapsed, LTA said in a statement.

It added: "Preliminary investigations indicate that the corbels supporting the pre-cast beams had given way. As a precautionary measure, LTA is checking all other work sites.

"Works at all LTA road and rail construction sites will observe a safety timeout this morning.”

LTA later clarified that construction works around Singapore are ongoing, and that the timeout involved only a review of safety measures and processes at the sites.

Corbels are structural elements jutting from a wall to help support heavy items. According to the LTA, the contractor, Or Kim Peow Contractors, was "carrying out works to cast the decking” for the new viaduct when it partially collapsed.

Eleven workers, from China. India, and Bangladesh, were working on top of the structure during the accident. One worker, a Chinese national, was killed. The others — six from Bangladesh, three from China and one from India — were taken to Changi General Hospital with injuries.

A hospital spokesperson said eight of the injured workers had to be admitted for treatment, while two others had been discharged. LTA said it was saddened by the latest accident and pledged to assist the families of those affected.

The authority said it was looking into whether there were any lapses or gaps that required urgent attention, as part of ongoing investigations with the Ministry of Manpower (MOM).

"LTA has directed the professional engineers who were responsible for the project to carry out detailed investigations into the design and construction quality of the affected structure. LTA engineers, contractors and personnel are on site working with SCDF and Police to manage the situation,” the authority added.

Or Kim Peow Contractors and one of its staff, Victor Tan Kok Peng, were convicted and fined earlier this week for a fatal accident at Yio Chu Kang flyover on September 22, 2015. One worker was killed and three others injured after the working platform they were standing on dislodged, and they fell 6.4m to the ground.

The company and Tan, a safety coordinator and site Supervisor, were fined US$250,000 (RM780,610) and US$12,000 respectively under the Workplace Safety and Health Act, according to a press release from MOM on Tuesday (July 11).

In the statement, the ministry’s director of Occupational Safety and Health Inspectorate, Chan Yew Kwong, lambasted Or Kim Peow Contractors as "a company that does not take workplace safety seriously”.

When contacted today, a project manager from Or Kim Peow Contractors told TODAY he could not comment as investigations were ongoing. — TODAY