PUB said they will be calling for a safety time-out to review and assess sewer construction works similar to the Tanjong Katong incident on Saturday (July 26). A sewage shaft failure was identified as the cause for the sinkhole which formed at Tanjong Katong Road South and swallowed a black car that day, said the agency in a statement issued on July 27 night. The car's driver, who managed to exit the vehicle on her own, was then rescued by workers at the site and later taken to hospital by the Singapore Civil Defence Force.According to the national water agency, a caisson ring at a PUB worksite at Tanjong Katong — where a 16-metre deep shaft was being built to connect three existing sewer lines — was observed to have failed at about 5.50pm on July 26. A sinkhole formed on the adjacent road at around the same time. It is still not clear what contributed to this failure, the agency added. Read more