At least two construction workers were killed and another three seriously injured after an accident on Monday morning at the worksite for the future National Art Gallery Singapore on Supreme Court Lane. It was earlier reported that one worker had died.

According to workers, the crane collapsed at 10.50am along with its concrete counterbalance weights, partially crushing scaffolding within the worksite. The site's main contractor is Takenaka.

The Singapore Civil Defence Force (SCDF) said that of the two men who were pronounced dead on arrival, one was trapped at a five-storey height in the scaffolding and had to be hoisted down using rescue ropes.

The injured workers have been taken to Singapore General Hospital and Raffles Hospital. The SCDF, which was at the scene at 11.33pm to determine if there are other fatalities or injuries, said it sent one fire engine, two fire bikes, four ambulances and three supporting vehicles to the scene.

One worker Sen Thil, 36, said that the crane had been lifting a load at the time and may have become overloaded. A spokesman for The National Art Gallery Singapore's said that investigations are ongoing to determine the cause of the accident. Work at the site has been halted, and workers told to return to their dormitories.

In July, the jib of a crawler crane at the same construction site snapped and landed on the raod but no one was injured then.