A metal cradle that snapped in half plunging two workers to their deaths 50 storeys below may have been overloaded, a source close to the investigation said.
The weight on the 11-metre-long cradle, which broke on Tuesday while in use outside a flat on the 55th storey of a luxury residential block near The Peak, may also have been unevenly distributed, with four workers and construction materials all on one end.
When the cradle snapped, two of the workers managed to cling to half of the cradle, which was left dangling, while the other two fell to their deaths.
Metal and other debris fell with them, including more than 10 bags thought to have been storing cement. These were scattered over a hillside and the podium of the Tregunter Tower 3 on Tregunter Path.
The cradle was designed to carry up to 1,300kg, the Electrical and Mechanical Services Department said.
But investigators are unsure how much weight the cradle was carrying when it snapped.
"Some of the bags we retrieved are empty," a police investigator said. Investigators were also unsure how many bags had fallen.
The source said that as well as possible overloading, the weight carried by the cradle may have been unevenly distributed, with the bags, buckets of water, tools and possibly the four workers all on one side when it gave way. Metal fatigue was also being investigated as a possible cause.
The platform provider said the structure passed a half-yearly check in October. A report on the incident must be submitted to the Labour Department within seven days.
Last night, police were still looking for the two workers who survived. Officers are investigating whether illegal labour is involved. People with information can call 9766 4868.