CHENNAI: A mother and her daughter were killed while her husband and another daughter were grievously injured when an over-speeding truck rammed into their car that had stopped at a traffic light on GST Road near Chengalpattu on Saturday night.

The deceased were identified as S Ranjini (36) and S Manasvini (7). Her husband, Sudarshan (37) and his elder daughter, Sathvika (10) survived with injuries.

Sudarshan is a software professional with a private firm in the city and also owns a cattle farm near Maduranthagam, police said. On Saturday, the family had gone there and were returning to their home in Thalambur (off Rajiv Gandhi Salai) when the accident happened, investigations revealed.

When they reached Pazhaveli near Chengalpattu, Sudarshan stopped his car behind an omnibus, which was waiting for the staff of a private firm to alight from another bus halted in front of it. While he was waiting for the traffic to clear, an over-speeding truck rammed into the car.

Upon impact, the car was smashed between the truck and the bus. Passerby who noticed the accident alerted the authorities, after which occupants in the car were rescued and taken to a hospital where Ranjini and Manasvini were declared dead on arrival.

Chengalpattu taluk police have registered a case and are investigating. Traffic was affected on the stretch for 4 hours as a result of the accident.