Officials said the bus on Route 55M had departed from the Tambaram Sanatorium bus terminus and was heading towards Kuruvanmedu. As it was the last bus on the route for the night, a large number of passengers had boarded the vehicle at Tambaram, leading to heavy crowding as it travelled via Vandalur and Padappai.

However, after crossing Padappai, the number of passengers reduced, with only around 15 people remaining on board.

While the bus was proceeding near Navalur Savadi village, the driver lost control and the vehicle veered off the road and overturned into a drainage on the right side of the road. Six passengers, including women, sustained injuries, said the police. Residents from the nearby village and motorists immediately rushed to their aid. Soon, officials from Padappai police station also arrived at the spot and the injured passengers were shifted to nearby private hospitals for treatment. The police have registered a case and launched an investigation.