SOIL erosion and a water leak caused by a burst pipeline are being blamed for a cave-in that killed one worker and injured four others at a Metro Line 7 construction site Thursday.

    The accident happened at 4 p.m. when five workers were using a tunnel-boring machine near the Nanqiao International housing estate near the Huanggang Checkpoint in Futian.

    The workers were replacing the tunnel-boring machine’s digging tools when the soil inside the chamber collapsed. The housing and construction bureau said at a news conference Friday that a burst water pipe above the tunnel was to blame for the loose soil.

    One worker was killed at the scene and three others who were slightly injured were taken to a hospital for treatment. A fifth worker, who was trapped inside the tunnel with leg injuries, was rescued at 11 p.m. Thursday, seven hours after the incident.

    After the collapse a sinkhole formed measuring 10 meters across and 3 meters deep. Two cars parked on the roadside fell into the hole, but there were no passengers in the cars.

    Officials say that the sinkhole won’t affect the structure of the Fuminxincun housing estate nearby.

    After the sinkhole was filled with water, gas supplies to the neighborhood resumed.

    The housing and construction bureau has ordered the project contractor to rectify any issues. Other Shenzhen Metro contractors have been ordered to launch safety checks. (Han Ximin)