A state-run bus and a car were trapped in a huge crater formed due to the metro rail work underway in Chennai's Anna Salai area.
The cave-in took place while tunnel boring work for the Chennai Metro rail was being carried out between Thousand Lights and AG-DMS.
According to reports, 35 commuters were evacuated from the bus and no major injuries have been reported yet.
The bus halted at the bus stop but the driver felt some movements and thought it to be due to tyre puncture. When the vehicle began to sink he realised the caving in of road upon which he immediately asked the passengers to get down.
A Honda City car also crashed into the crater formed. Both the vehicles have been pulled out using cranes.
"The bus had stopped and some people were getting out. The road caved in slowly and that's perhaps why people could escape," news minute quoted an eyewitness as saying.
This is not the first time that stretches have caved in due to tunneling work in Chennai.
Its the second such incident that has taken place in the area in last ten days. On March 30, a road in same area caved in and led to traffic being thrown out of gear for several hours.