SINGAPORE, July 28 -- Singapore's national water agency PUB said yesterday it will call for a time-out to review the safety of ongoing sewer works similar to those near the sinkhole that opened up along Tanjong Katong Road on Saturday.

According to Channel News Asia, the sinkhole, about two to three metres deep and as wide as two lanes, appeared adjacent to an active PUB worksite involving the construction of a 16-metre-deep shaft linking three sewer lines.

PUB said a "concrete component in the shaft failed at around 5.50pm", around the same time a car plunged into the road after the collapse.

The agency identified the failed part as a caisson ring, describing it as "a watertight retaining structure that allows water to be pumped out, ...