Six people are killed in China as a sinkhole opens up at a bus stop.
The BBC report that 6 people were killed and a further 16 injured as a number of pedestrians, as well as the bus, were engulfed by the massive sinkhole, estimated as 10m in diameter.
An explosion is seen to take place on the CCTV footage, which shows the incident, shortly after the bystanders and vehicles fell into the hole, which is most likely to relate to power cables being damaged on entry.
Buried Services and the appearance of sinkholes can go hand in hand.
GEOTEC Surveys carried out a GPR survey in 2017 after a bus fell into a sinkhole at a Railway Station. In this instance our objective was to detect and map any evidence which may relate to the presence of saturated ground conditions as well as additional sub-surface voids or anomalies, and the position and depth of a known culvert, as shown below.
Extract of Survey Results
In many instances, leaks from water or drainage systems, together with periods of heavy rain can cause a wash around existing utilities which displace the surrounding soil and then create a void beneath a surface (usually held together by tarmac or grass roots, for example).
The wash takes place gradually, however the resulting implosion of the above surface happens suddenly and often when put under force (by a bus, for example).