A Chennai sinkhole opened on Old Mahabalipuram Road near Tidel Park on Thursday morning, trapping and overturning a car beside an underground Metro construction site and causing severe congestion between Tidel Park signal and Taramani. The two occupants escaped without injuries.
The incident occurred at about 10.45am near Thiruvanmiyur MRTS, when a white SUV travelling from Indira Nagar began sinking as it moved past the median. The driver, identified as Praveen, said the occupants had stopped at a signal before the road gave way beneath them. They exited the vehicle immediately, after which the car overturned and disappeared into the crater.
A video from the site showed an MTC bus attempting to pass the SUV and a Metro rail barricade as the vehicle fell into the opening. The car was removed later in the afternoon, while traffic officials put diversions in place to manage the resulting congestion.
Vehicles, except two-wheelers, approaching from the CPT side were diverted at Indira Nagar Junction towards Indira Nagar Water Tank Road. Motorists using Indira Nagar Second Avenue were directed to turn right towards Water Tank Road and continue towards Tidel Park through the Thiruvanmiyur junction. Traffic between Tidel Park signal and Taramani moved slowly after the collapse.
Officials at the site said underground utilities had been shifted before the Metro work began and that a rupture in a water pipeline was therefore unlikely to have caused the collapse. They said the operation of a tunnel boring machine or other underground construction activity could have contributed to land subsidence. The cause had not been established when the response work began.
The Chennai Metro Rail Ltd said the sinkhole was about 30 metres from the shaft where underground station work was under way. It confirmed that tunnel boring machine Bhavani was excavating a tunnel from Thiruvanmiyur towards Taramani as part of Phase-2 Corridor-3.
CMRL said the vehicle had been lifted from the sinkhole and that backfilling with concrete was in progress. The agency added that safety and site-protection measures were being taken and that a technical enquiry was under way. The investigation is expected to determine whether the road failure was connected to the nearby underground construction activity or another subsurface condition.
